L IVE REEF FISH. Inside this issue. Secretariat of the Pacific Community. Editor s mutterings. The live reef fish export and aquarium trade

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1 ISSN Secretariat of the Pacific Community L IVE REEF FISH The live reef fish export and aquarium trade Number 7 May 2000 I N F O R M A T I O N B U L L E T I N Editor and group coordinator: Bob (R.E.) Johannes, 8 Tyndall Court, Bonnet Hill, Tasmania 7053, Australia. [In Australia: phone: ; fax: From overseas: phone: ; fax: bobjoh@netspace.net.au] Production: Information Section, Marine Resources Division, SPC, B.P. D5, Noumea Cedex, New Caledonia. [Fax: ; cfpinfo@spc.int; Produced with financial assistance from France and Australia. Editor s mutterings Baby sharks newest Live Reef Fish Trade target As this edition went to press I received worrying reports from two regular Indonesia-based contributors to the SPC Live Reef Fish Information Bulletin Mark Erdmann in Sulawesi and Jos Pet in Komodo. Mark says that during a recent trip around Sulawesi, 13 different villages claimed that within the last three months, large live fish transport boats were moored offshore. These vessels were accompanied by around 20 small fiberglass skiffs engaged in catching baby sharks (along with the usual groupers and humphead wrasse, which are growing extremely scarce in shallow water in the area). Meanwhile, Jos reports that shark pups, especially reef blacktips, are being taken in very large quantities from Komodo and are being shipped by the boat loads. Jos says that for the past year or so, baby shark has been featured on tourist restaurant menus in Labuan Bajo. He surmises that these may be the fish that die during capture or storage. This sounds plausible, considering that many sharks (including reef blacktips) must swim continuously in order to get enough oxygen and so will probably not tolerate life in small cages as well as groupers and wrasse. Sharks are slow-growing, late-maturing fish that have only a handful of babies. Reef blacktips, for example, have only 1 3 pups. For these reasons, experts say that that most shark populations cannot withstand a fishing mortality even as low as 5% of the existing population each year. Given the current pressure on shark populations by shark finning operations in the region, this new fishery is clearly a cause for concern. I would be very interested in receiving reports (even if just a paragraph of two) from other areas on the targeting of shark pups for the live reef fish trade. Inside this issue The industry perspective: Wholesale and retail marketing aspects of the Hong Kong Live Reef Food Fish Trade by P.S.W. Chan p. 3 Current status of the live reef fish trade based in Hong Kong by P.S.W. Chan p. 8 The Second International Conference and Exhibition on the Marketing and Shipping of Live Aquatic Products 99 by Y. Sadovy p. 10 Ciguatera management by R.J. Lewis p. 11 Grouper/Wrasse Species Survival Group formed by Y. Sadovy p. 13 Review of grouper hatchery technology by M. Rimmer p. 14 Cyanide fishing on Indonesian coral reefs for the live food fish market What is the problem? by P.J. Mous et al. p. 20 Cyanide-free net-caught fish for the Marine Aquarium Trade by P.J. Rubec et al. p. 28 and more... M A R I N E R E S O U R C E S D I V I S I O N I N F O R M A T I O N S E C T I O N

2 2 SPC Live Reef Fish Information Bulletin #7 May 2000 Industry perspective The perspective of the live reef food fish industry has been poorly represented in this publication. The problem has been finding appropriate people willing to write. Fortunately, Mr Patrick Chan, Chairman, Hong Kong Chamber of Seafood Merchants Ltd. has come to the rescue in this issue with two information-filled articles on the Hong Kong industry s perspectives and problems. Various industry reports indicate that gravid female coral trout are subject to considerably higher mortality in holding facilities and in transit than males or non-gravid females. If this is the case, it is one more reason for not targeting spawning aggregations for the live reef food fish trade. Unfortunately there is no published research describing the relationship between female sexual maturity and stress tolerance of groupers or any other fish. Much research has been published on the effects of stress on fish reproduction but very little on the converse the influence of reproductive status on stress tolerance. Here is a research opportunity begging for the attention of fish endocrinologists and physiologists. Aquaculture cost/benefit Mike Rimmer makes the point in a recent article on Reef Fish Aquaculture (see Noteworthy Publications on page 39 of this issue), that the costs for aquaculture research and development (R&D) are very high, but the financial rewards to a country can be much larger. The cost of establishing the Atlantic salmon industry in Norway, for example, was estimated at about US$ 55 million over eight years, but the industry is now valued at ten times that amount per year. The US catfish industry cost about US$ 42 million for initial R&D, but is now worth more than six times that amount annually. While selling the virtues of aquaculture to our politicians and others, however, we must discourage them from looking upon it as an alternative to improved fisheries management. By aquaculturing reef fish, we may take some of the pressure off wild stocks of some species, but aquaculture by itself is not enough. The need for improved fisheries management in much of the coastal tropics is urgent, and aquaculture, no matter how successful it might some day become, can never replace improved management of wild stocks (e.g. see Mous et al., this issue, p. 20). Moreover, if researchers don t come up with suitable, vegetable-based foods for carnivorous fish such as groupers, their expanding culture will ultimately place insupportable pressures on wild stocks of the species used as feed. Eggs and stress More debate sought Neither this editor nor the SPC or TNC, who support this publication, always agree with what goes into these pages. I believe that this is the way it should be. Some of the articles in this issue in particular, put forward controversial opinions. They offer good starting points for constructive debate. If you disagree with, or support, any of these opinions, let us know in the form of letters to the editor, short or long articles, or opinion pieces. Western tropical Atlantic countries leave us for dead Once again a western Atlantic country demonstrates why this region is so far ahead of the Indo- Pacific in protecting reef fish spawning aggregations. The Bahamas government has recently approved the establishment of five no-take marine reserves. All of these sites contain known Nassau grouper spawning aggregations. Although stocks of Nassau grouper in the Bahamas appear to be healthy, these closures, coupled with other research activities, are being implemented to ensure that conservative management measures are taken as a precaution against the stock collapses that have occurred in other locations that once held stocks of Nassau grouper. Cyanide doesn t kill fish??? Among the 328 people that attended the First International Conference on Marine Ornamental Species in Hawaii last November the position was taken that fish exposed to cyanide recover, according to Robert R. Stickney (Marine Ornamentals 99. World Aquaculture 31(1): p. 4). I suppose I ought to make some comment on this assertion, but it leaves me speechless. Bob Johannes The views expressed in this Bulletin are those of the authors and are not necessarily shared by the Secretariat of the Pacific Community and The Nature Conservancy.

3 SPC Live Reef Fish Information Bulletin #7 May The industry perspective: Wholesale and retail marketing aspects of the Hong Kong Live Reef Food Fish Trade 1 by Patrick Chan 2 Introduction Eating live seafood (i.e. seafood kept alive until immediately before cooking) is a strong tradition among the people along the south-east coast of China. In recent years this culture has spread to the people of neighbouring countries with large Chinese populations, including Taiwan, Singapore, Malaysia and Thailand. The Chinese word for fish has the same pronunciation as the word for plentiful and is an important symbol in traditional Chinese agricultural society. Fish are essential at all dinner receptions. In Hong Kong (HK) 95 per cent of all restaurants are Chinese, and most serve live seafood. Each year about 30,000 to 35,000 metric tonnes of live reef fish are imported into HK with a total wholesale value of US$ 490 million. This does not include minor amounts of live reef fish caught by local fishermen from the reefs in the South China Sea. Although reef fish dominate the live seafood market, also imported live are lobsters, mantis shrimps, crabs, shrimps, abalone and certain clams. Small quantities of coconut crabs, scallops and giant freshwater eels are imported live as well. Fifty-five to 60 per cent of the imported live reef fish is re-exported to the People s Republic of China (PRC). It was first exported to the Shenzhen Economic Zone close by HK, and subsequently to Beijing, Shanghai and other large cities in PRC. Preferable types of live reef fish Common reef food fish eaten in the region are shown in Table 1. Red coral trout, Plectropomus areolatus, is the most common medium-priced fish in both HK and PRC. Traditionally red means good fortune among the Chinese. Chinese hosts like to present a red coral trout at wedding, birthday or other celebration dinners. At present almost all red coral trout are caught wild. The wholesale price of these fish is about US$ 38/kg. In HK, those who cannot afford coral trout, Plectropomus spp., often buy less expensive groupers (see Table 1), especially green groupers, Epinephelus malabaricus and E. coioides. These sell for about US$ 20/kg. They come mainly from aquaculture and the supply is therefore very steady. In PRC people may substitute certain freshwater fish if they cannot afford the more expensive reef fish. After the economic crisis in Southeast Asia, highpriced reef fish became less popular. But humphead wrasse, Cheilinus undulatus and high-finned grouper, Cromileptes altivelis, remain expensive because the supply is limited. They sell for about US$ 64/kg. In PRC it has become a tradition to serve these fish at business reception dinners in order to demonstrate the ability of the host to afford expensive food. Officials from state-owned organisations also like to order expensive seafood at their social gatherings because the bills go to their organisations, although recent reforms have curbed this practice. In HK the situation is different. As well as consuming live reef fish at social functions, people will order them after making some easy money, like winning at the racetrack or making a big profit on the stock market. Countries of origin About 50 per cent of live reef fish are imported from Indonesia, closely followed by the Philippines, Australia, Maldives, Vietnam, Malaysia and Thailand. Imports from Indonesia began in Most of the suppliers are Indonesian Chinese who normally set up floating cage stations and purchase their fish from fishermen. Fish are held in these cages until there are sufficient to notify HK 1. Derived from two papers given at the Second International Conference and Exhibition on Marketing and Shipping Live Aquatic Products '99. Seattle November Chairman, Hong Kong Chamber of Seafood Merchants Ltd. and General Manager of Brightfuture Industry Limited. bil@powernethk.com

4 4 SPC Live Reef Fish Information Bulletin #7 May 2000 Table l. Scientific, English and local names for common Live Reef Food Fish in Hong Kong. Scientific name English name Local name High priced species Cheilinus undulatus Humphead, maori or Napoleon wrasse So Mei Cromileptes altivelis High-finned or mouse grouper, barramundi cod Lo Shu Pan Medium priced species Plectropomus leopardus Spotted or leopard coral trout Sai Sing Plectropomus areolatus Red or squaretail coral trout Tung Sing Lower priced species Epinephelus polyphekadion Flowery grouper Charm Pan Epinephelus malabaricus Green or malabar grouper Ching Pan Epinephelus coioides Brown-spotted grouper Ching Pan Epinephelus bleekeri Orange-spotted or green grouper Chi Ma Pan Epinephelus fuscoguttatus Tiger or flowery grouper Lo Fu Pan buyers to send a live fish carrier to collect them. This is the way the operation will continue in most of Indonesia because there is no other practical means of transport. However, in big cites like Jakarta and Denpasar where international airports are available, suppliers operate their own live fish carriers and buy from fishermen from regions up to 4 to 5 days away by boat. These catches are sent to HK by air along with live lobsters. Today suppliers from Cairns in Australia, Manila in the Philippines, Sabah in Malaysia, Thailand and Vietnam rely heavily on air transportation; now more than 80 per cent of the catches from these countries are sent to HK by air. Exports from Pacific Islands and other remote areas As most of the Pacific Islands do not have direct flights to HK and the distance is very far, it is neither economically nor technically feasible to send live reef fish to HK by air. Export by ship is the only possible way. Large live-fish carriers are now able to take fish from some countries such as Fiji Islands, Kiribati and Seychelles in the Indian Ocean. However, the ships require 20 tonnes or more of fish or the transportation cost cannot be justified. Operators from Pacific Islands who wish to export live reef fish to HK are encouraged to establish contact with an importer in HK who will be able to arrange for a live reef fish carrier to take their fish. Normally the importer in HK is happy to provide technical backup and training to native fishermen. Hong Kong Chamber of Seafood Merchants Ltd. is able to assist. Transportation by sea Currently, live fish traders in HK are using two types of live fish transport vessels (LTVs). The first is the traditional HK fishing vessel. Its design was introduced from Scotland. It was based on that of metal hull trawlers operating in the North Sea, which were required to operate in rough seas. HK shipbuilders followed the design but built their ships from wood. Almost 99 per cent of HK fishermen use wooden vessels because this exempts them from being required to obtain proper navigation certification. The policy exists because the majority of HK fishermen are poorly educated and it is not possible for them to attend navigation training courses. Some of these vessels are built with live wells for use in live reef fish transport. Initially such vessels were about feet long with engine capacities of less than 300 HP. Now some LTVs are up to 120 feet long with engine capacities of up to 1500 HP. Such vessels can hold up to 20 tonnes of fish. A few traders use metal-hulled LTVs. Second-hand LTVs were also bought from Japan, while others in the trade converted small cargo ships or tuna ves-

5 SPC Live Reef Fish Information Bulletin #7 May sels. Generally the live-well capacity in metalhulled vessels is larger than that of similar-sized, timber-hulled vessels, as the latter require more live-well partitions to support the hull. Both types have water inlets and outlets in the hull, providing good water circulation during sailing. The water flow is up to ten times the holding capacity per hour. But all carriers must have strong pumping systems to maintain water flow when the vessels are stationary, as when loading or unloading. The officer who supervises loading must be experienced and observant; the success of each shipment depends heavily on him. Special attention must be paid to the following during loading and unloading. During low-tide periods, inshore waters typically have a lowered oxygen content and the water may be especially warm. It is thus risky to load or unload fish under these conditions. Low atmospheric pressure causes fish to move to the surface where the temperature is higher and the oxygen concentration lower. Fish are more active in warmer water; the oxygen consumption of fish may double or triple with a 10 C rise in temperature. This is of special concern when fish are placed under stress, as when being loaded or unloaded. Also, when the fish are disturbed they tend to huddle together, which may cause a drastic localised drop in oxygen level. Good water circulation helps reduce these problems. Loading fish to different live wells in rotation can also help. When the live wells are loaded to 70 per cent of full capacity it is desirable to inject pure oxygen into the water through diffusers. The holding capacity of live wells depends on the type of fish involved. Snapper are more active than grouper and thus require more space. The size of the fish is also important, since small fish consume more oxygen per unit of weight than large fish. Average holding ratios are between 8 and 14 to 1, i.e tonnes of water per 1 tonne of fish. HK buyers prefer to select and weigh fish immediately before loading. This is an effective way to avoid theft and mortality due to mishandling after weighing. It is not a good arrangement, however, as it is more stressful to fish. Transportation by air With more experience and improved skills and equipment, more and more live seafood is being transported by air, especially the higher-priced products. Generally speaking, fish are the most difficult live seafood item to transport by air. But with good practices their survival rate is very good if the total transportation time is within 24 hours. Decline in water quality is the biggest problem declining oxygen content, carbon-dioxide buildup, detrimental changes in ph, detrimental changes in temperature, and build-up of fish wastes. The loss of the protective layer of mucus on fish can also be a problem. Every minute counts when packing live seafood for air transport. An experienced operator knows how much time his packing team needs to pack a box, and plans so that the team will start packing with just enough time for them to finish their task. Ideally the packing centre should be no more than a 30-minute drive from the airport. Running costs can be reduced if seawater can be directly pumped to the packing centre. This also cuts down the cost of water holding facilities, which are essential for any packing centre. An immediate water supply is needed for when the water in the holding tanks suddenly turns bad. Fish should not be fed for at least 24 hours before they are packed to avoid vomiting of undigested food which will pollute the water. Live reef fish can be given a freshwater bath for 2 3 minutes when they are first delivered to the centre. The freshwater tends to cause the fish to vomit undigested food and it also kills various external parasites. The temperature of the holding water should be in the range of C. Since reef fish typically live in water ranging in temperature from about 24 to 30 C, gradual reduction in temperature will render the fish less active and less stressed. The water in the holding pools should be well circulated and must go through a bio-filter to neutralise ammonia. Injecting air using an air compressor and diffuser can raise oxygen content. The water temperature should be lowered another 2 3 C prior to packing. The chilling process should be slow and completed within four hours. Packing water should be the same temperature as that in the holding tank. Anaesthetic is used if the fish are packed in polyethylene bags. In addition to cooling, it is a double measure to ensure that the fish will not become too active when the water temperature rises during transport. Anaesthetic use is not approved for food fish and other seafood in most markets, but it is commonly used in Southeast Asia. Even if anaesthetic were approved, the purge period would probably be greater than the usual pre-purchase holding time.

6 6 SPC Live Reef Fish Information Bulletin #7 May 2000 Australian live-fish exporters were the first to use plastic bins to transport live fish by air to HK. The bins are insulated and have a one-tonne water capacity. A battery-operated air pump is fitted at the upper compartment of the bin to inject air into the water through a diffuser. A simple skimmer device is also installed on the upper compartment. The capacity of a bin is about 240 kg of live fish. The survival rate is very good if the cargo is delivered to the buyer within 24 hours. As the water temperature can be well maintained in these bins no anaesthetic is used. However returning the bins is costly. To pack live fish in polyethylene bags and expanded polystyrene boxes requires a skilful working team. The water is cooled as described above. Three to four kg of water are used per one kg of fish, depending on the type of fish and length of flight time. The box is passed on to a second worker who is responsible for the injection of pure oxygen into the bag; the bag is then secured with an elastic band. The box is then passed on to the final worker who checks the packing, adds coolant, and seals the polystyrene box with sealing tape. An experienced working team can process one box per minute. The market chain To people from elsewhere, the price of live reef fish in HK seems very high. This has created the impression among foreign suppliers that they have been deceived by HK buyers, and the prices they obtain from the latter are too low. In fact, imported live fish must go through several traders before they reach the restaurants, and each requires a profit. In addition the operations of importers and wholesalers require considerable capital. The annual business turnover of a major wholesaler in HK may reach US$ 25 million. One 15 t shipment of fish may involve US$ 250,000 and is unaffordable to retailers. The retailers buy the fish from wholesalers and in turn control the market distribution. Restaurants are the main end users. Live reef fish importers operate one or more livefish carriers. Foreign agents are responsible for the arrangement of adequate quantities of fish and clearance to bring the fish into the country. Larger importers may own floating cage stations in HK and will also act as wholesalers if they have a large holding capacity. Small importers will sell their fish to wholesalers and the latter will sell the fish to retailers after taking 8 14 per cent profit. Retailers will hold their fish in their shops until they sell them. Marketing officers in these shops telephone the restaurants in their sales network each morning to take orders. The fish will be delivered to the restaurants the same afternoon. As there is risk of mortality during the hold period, retailers will normally take a profit of 24 35% and the restaurant will then mark the fish up by %. As shipping skills have improved in recent years, overseas suppliers are increasingly sending live reef fish to HK by air. As the quantity in each air shipment is relatively small, a number of retailers have started importing live fish by air, avoiding the need to go through wholesalers. At the moment the situation is chaotic and the identities of wholesalers and retailers are hard to define, although wholesalers retain the leading role in the trade. Payment and trading rules Wholesalers normally settle their account with importers within one week of sale. If the fish cannot be sold immediately the wholesaler is required to buy the fish at a price agreeable to both parties and the risk will then be transferred to the wholesaler. The relationship between importers and wholesalers is close, and it is not uncommon to see wholesalers providing financial aid to importers, especially when the latter s transport vessel needs urgent repair or an additional deposit is needed for a future shipment. Retailers are supposed to settle their bills within 10 days to 2 weeks. However, as the economy slumped during the past two years, unsettled accounts have sometimes dragged on for 4 6 weeks. Retailers get higher profits from restaurants. However the normal restaurant payment term is days. The payment from restaurants associated with big hotels is even slower. In addition, restaurant operators sometimes pressure retailers into subscribing to dinner coupons during special business promotions, which may cost several tens of thousands of HK dollars per year. Retailers also pay three per cent of the total annual sales as a commission for restaurant staff. It might appear that the benefits are stacked in favour of the restaurateurs. However HK is one of the most expensive places to live in the world and restaurateurs are required to pay very high rents and salaries. Nevertheless, the restaurant business can be very profitable. Re-export of Live Reef Fish to PRC The import tax on seafood imported to PRC is 17 per cent. Other government departments also levy additional charges. The situation is confusing and varies from city to city. Organisations with strong connections may get quotas to import seafood at much lower cost.

7 SPC Live Reef Fish Information Bulletin #7 May For the past seven or eight years, much seafood has been imported through the small port of Yantien, located on the eastern border of the New Territories of HK. A designated fish-culture area is adjacent to Yantien and the fish farmers cooperative there is able to sell its fish with an import tax of only three per cent. It is an open secret that live fish from elsewhere are often funnelled through this cooperative. Bribes are often given to import officials to facilitate the import clearance of such fish. Recently the central PRC government has taken drastic action to eliminate smuggling, and this import channel has thus become increasingly difficult. Several shipments of seafood have been held and heavy fines imposed, but the import of live reef fish has not stopped. In the past, operators in big cities like Beijing and Shanghai relied on retailers to supply them with seafood from Yantien. Problems often occurred because of retailers absconding with cargoes after securing a credit line from traders in Yantien. The chance of catching them was slim because they operated with just a truck and a hand phone. Many HK seafood operators who had set up shops in Yantien a few years ago suffered huge losses from such unreliable clients. Now operators in Yantien, most of them local people, are very cautious concerning who they sell their product to. They are also able to change the RMB (PRC currency) into HK dollars in the black market, which helps them survive financially. Following the opening of HK s new airport, a new and important live-seafood entry point was established in Shekou, which is an industrial zone adjacent to the western border of HK. A few HK transportation companies are now cooperating with state-owned organisations that have seafoodimport quotas. Several fishing vessels now travel between Shekou and Tung Chung, which is a port only five minutes by truck from the HK airport. This channel can save a lot of time and the service charge is significantly less that the normal import duty. Shekou is also convenient for those wishing to send seafood to other big Chinese cities like Shanghai and Beijing. The Shenzhen airport is just a 25-minute drive from Shekou. Some HK operators have set up holding centres in Shekou and provide holding and re-packing services for the liveseafood traders in PRC. import quotas and tariffs. There are no valueadded or general service taxes. However, cargohandling charges are about HK$ 1.4 (US$ 1 = HK$ 8 in February 2000) per kg. Normally the consignee will appoint a transportation company to take the cargo from the airport. The appointed truck driver can collect the cargo on production of the airway bills and letter of authorisation from the consignee or the company seal. Truck rental normally costs between HK$ , depending on its capacity. If fish are shipped in polystyrene boxes, there will be additional labour charges. The airway bill must be prepared by the shipper s cargo-handling agent. The original copies go with the cargo and a photocopy is faxed to consignees. A certificate of origin is usually not required, although it may be required under certain circumstances. An import and export declaration must be made by the consignee within 14 days after the import or export of any article other than cargo for transhipment, transit, or for exhibition purposes and with a value of less than HK$ 1,000. The declaration is used mainly by the Census and Statistic Department to enforce the regulations relating to import and export. Goods at the airport are physically inspected on a selective basis after inspection of the airway bill. The custom hours for general cargo are Monday through Friday, 8 am to 3 pm, but live products can get clearance outside these hours. Live marine fish do not require a health certificate (although dead fish and all shellfish, crayfish, etc. do). The HK International Airport is about 50 km from the city and transport vehicles take 35 to 40 minutes to reach urban areas via a good highway network. However, a total of 2 3 hours will be needed for the transportation workers to clear the cargo and deliver to the consignee. The air temperature could reach 35 C between mid-may and late September and sufficient coolant must be used to maintain packing temperature. Import formalities Hong Kong is a free port and does not levy any customs tariffs or duties on imports. It maintains no anti-dumping laws, countervailing duty laws,

8 8 SPC Live Reef Fish Information Bulletin #7 May 2000 Current status of the live reef fish trade based in Hong Kong Patrick S.W. Chan 1 At the end of 1999, the live reef food fish trade based in Hong Kong was experiencing several difficulties. They involved two issues: 1. Supply of wild-caught, market-sized fish (mainly groupers but also including some other families of reef fishes such as the wrasses), and 2. Prospects for increased mariculture to supply the industry and meet consumer demand. Wild-caught fish supply Following the Asian economic downturn starting in late 1997, both wholesale and retail prices declined by about 50 per cent compared to the peak prices of earlier years. The industry has been experiencing a number of difficulties as a result and is now operating on a much finer profit margin (less than 10% gross) than before. These problems have been worsened by other factors, both inside and outside Hong Kong. Within Hong Kong, wholesalers have been affected because restaurants, also affected by the economy, increasingly delay their payments. In addition, reduced demand means that when large quantities of fish are brought into Hong Kong by ship, they cannot be sold quickly. This is particularly difficult during the northern winter, when the sea temperature in Hong Kong is lower than 18 C, as reef fish cannot survive at such low temperatures and therefore cannot easily be stored while awaiting sale. Shipments of smaller quantities of fish, which would be more appropriate for the current market demand, are not viable economically because of high transport costs. The market price in Hong Kong is now so low, that to date, more than 20 per cent of live reef fish operators have ceased to operate. Prices of fish decreased by a further per cent for about three months following several incidences of sea imports of large numbers of ciguatoxic fishes. Both the government and the industry have done their best to prevent toxic fishes from being imported into Hong Kong. The Health and Agriculture, Fisheries and Conservation Departments have carried out regular random checks on imported reef fish. Traders have stopped buying fish from Kiribati, Papua New Guinea, and Sri Lanka, from where the toxic fish were reportedly imported. Traders also agreed to stop selling highrisk fish, such as moray eels and red snapper, Lutjanus bohar. There has also been a marked change in the transport mode of imported fishes; the current ratio of imported fishes by ship and air is 45/55 compared to a ratio of about 65/35 in the past. Sea imports have dropped markedly. Local traders use live-fish carriers to collect the catches from the fishermen. But the fish will then be delivered to packing centres, normally located in cities with an international airport, for export by air. This kind of trading continues to grow because it requires lower running capital and the risk is smaller than if fish are stored until enough have been accumulated for a large export shipment. Since the transport of large quantities of fish by ship is not economically viable, there has been an increased demand for more small shipments of fish by air. Air cargo space has become more limited, however, as more fish are being sent by air. Moreover, fish sent by air may suffer from lack of sufficient oxygen during transport. There is no way to tell quickly if a fish is sick and likely to die within a short time after arrival. Other factors, external to Hong Kong, have also affected the supply of fish to Hong Kong businesses. In Maluku and Sumatra in Indonesia, there has been serious social unrest. Given that major fish supplies come from Indonesia, especially Maluku, this has affected the amount of fish being exported by sea. The situation in most big cities within Maluku is out of control and Chinese have become a target of attacks. As most of the agents and operators are Indonesian Chinese they have been forced to leave Maluku. Most of the fishing has now stopped because there are no longer any buyers and it is too 1. Chairman, Hong Kong Chamber of Seafood Merchants Ltd. and General Manager of Brightfuture Industry Limited. bil@powernethk.com

9 SPC Live Reef Fish Information Bulletin #7 May dangerous for Hong Kong people to be there. Many people were killed in the confrontations and the situation has been much worse than was apparent from news reports aired in Hong Kong. Organised cyanide fishing in Indonesia has almost ceased completely because, using this method, divers can only operate in shallow water (no deeper than 30 m) and target fishes are no longer readily found in shallow waters. In 1994, there were more than ten local companies who ran big fishing vessels with teams of divers catching fish using cyanide. In those days, a vessel could catch kg of fish per day; catches in 1998 declined to kg/day. All these companies had powerful connections but they are still required to pay substantial operation fees to the authorities concerned. Hong Kong traders are also required to pay a very heavy export fee to navy, army, police, customs, immigration, judicial staff and even to journalists. These extra costs have become unaffordable because of the poor market in Hong Kong. Many Hong Kong traders therefore gave up trading in live fish in Indonesia. The last company that ran two fishing vessels with divers closed in the first half of Before 1995, 75 per cent of the reef fish, mostly humphead wrasse, from east Indonesia was caught by cyanide, but now the situation has greatly improved since divers are no longer able to see the fish in shallow areas and it is very difficult for them to catch fish at depths beyond 30 metres. It has become more appropriate and easier to use hook and line for the remaining fish in deeper waters. At present, there are local fishermen still catching fish with chemicals (commonly cyanide but also Derris root) but the authorities rarely stop them. These fishermen are too poor to pay the fine and if they are jailed, their family members will go hungry. These fishermen have been using chemicals to catch fish since long before Hong Kong traders came to Indonesia. In the past their catches were salted and dried and sold to local traders once every one or two months. Fish from mariculture One alternative and safe (i.e. ciguatera-free) source of fish for the live reef fish trade is mariculture. Hong Kong currently has a small mariculture sector which has regularly been producing about 3,000 metric tonnes (t) of fish annually through the grow-out, in net cages, of wild-caught (imported) juveniles (last year, however, because of red tides, production was just over 1,000 t). Given that the areas suitable for culture in Hong Kong are limited and water quality is deteriorating severe problems with red tides have recently resulted in high fish mortality there appears to be little opportunity for cage culture to expand in inshore waters. In order to increase the supply of high-quality fish, such as groupers, for the live reef fish trade, the mariculture industry, therefore, needs assistance and diversification. Current problems that need to be addressed include: High Hong Kong wages for workers and problems in hiring foreign workers; Difficulties in obtaining good-quality trash fish at reasonable prices; Limited provision of medicines to treat fish because of the tight import controls on medicine; Lack of technical expertise or back-up from government; Lack of local supply of fish fry/fingerling all must be imported, and Lower production costs in People s Republic of China, Thailand, and elsewhere, making Hong Kong prices for cultured fishes not competitive. Since last year imported Epinephelus bleekeri fry caught in Thailand have been sick, the black grouper fry supply from Sri Lanka has dropped substantially and fry supply from Thailand and Vietnam this season appears to be low. These factors, combined with the 50 per cent drop in the price of fish in Hong Kong in the past three years, provide serious challenges for a viable mariculture industry in Hong Kong. One possible approach to these problems would be for Hong Kong to develop its own hatchery to produce vaccine-treated fry/fingerlings and to consider moving the grow-out operation to land. Good quality, cheap, pellet fish feed also need to be developed in order to improve growth, reduce the risk of disease and reduce the need to catch wild fish for fish-feed purposes. With the exception of the humphead wrasse, hatcheries in Taiwan, Japan, Australia and Malaysia are able to hatch fingerlings for most of the reef fishes preferred by the markets in Hong Kong and People s Republic of China. If the mariculture sector in Hong Kong were to be given some help to overcome the problem of high mortality, local products would still be able to compete with the fish from other countries because we could save on freight costs, which are very high. In the long run, mariculture is the solution to the problem of over-fishing but for this idea to be supported a lot remains to be done by the authorities and other relevant units.

10 10 SPC Live Reef Fish Information Bulletin #7 May 2000 The Second International Conference and Exhibition on the Marketing and Shipping of Live Aquatic Products 99 by Yvonne Sadovy 1 The above conference was held from November 1999, in Seattle, Washington and covered the marketing and shipping of finfish, shellfish, ornamentals (aquarium fish) and plants. A wide range of subjects was addressed with an interesting mix of business, science, advocacy, capture and culture, presented by government officers, biologists, businessmen, engineers, conservationists, fishers and mariculturists, to name but a few. Topics ranged from physiology to social, ethical and humanitarian considerations, wildlife and health, regulations and the problem of introducing exotic species, to live-holding-system engineering, live shipment issues, resource management and marketing. This range reflects the many areas involved in the business of maintaining and marketing live aquatic organisms. There was much interest in the high-value Hong Kong/mainland China live seafood market and the possible acceptability of species, including cold-water species, currently not included in the Hong Kong-based trade; New Zealand, Australian, and North American companies were among those exploring trading possibilities in fishes and invertebrates. A brief summary is given of just a few of the 40 or so interesting talks representing some of the range of subjects presented. The selections inevitably reflect my own interests or addressed areas that were new to me. Moreover, this summary is by no means exhaustive; the Proceedings will be out soon and I did sneak off briefly to take a look at downtown Seattle! Based in Hong Kong, I am aware of the trade in live animals that come from coral reefs. However, there has been a live fish fishery off California for the local Asian market since at least 1988 (see Tegner & Dayton, SPC Live Reef Fish Information Bulletin 2: 25 26) which includes various rockfishes (scorpaenids), kelp greenling, ling cod and sheepshead wrasse. Data have been collected since 1993 and there are over 1,000 fishers involved, active from the intertidal zone to a depth of 20 fathoms. There is concern about overfishing. For ornamental (marine aquarium) fisheries, talks covered concerns regarding hit-and-run types of collecting and the advantages and disadvantages of the Florida-based fishery; the marine aquarium fishery is managed but not based on biological information, simply based on some compromise acceptable to both government authorities and fishers. Humanitarian concerns were also expressed in the treatment and sale of live organisms in general; the need for a practical code of ethics was identified. Concerns were also expressed regarding the overfishing of blue crab in some areas. Interesting presentations were given on physiological differences among species that make them more or less able to withstand the stress involved in capture and shipment. Even closely related species (the example given involved crabs) may differ in this respect; a difference that could make a species more or less suited to live trade. An understanding of the stress response is also clearly important for reducing mortality and maintaining quality (and, dare I say it, for reducing cruel and unusual punishment!). One speaker suggested that data on mortality would be useful in addressing such problems and for working towards practical solutions. It is clear that such issues cannot be ignored; there has been at least one lawsuit filed to ban trade in live marine organisms in the United States. Public interest and concern over the treatment of live organisms, in the West at least, has been growing in the last 30 years. We learned about the intricacies of the HACCP (Hazard Analysis Critical Control Point) methodology. About 30 per cent of seafood is traded internationally. There are several problems with current international trade that involve food safety concerns, such as paralytic shellfish poisoning and ciguatera fish poisoning. A major problem in applying the HACCP guidelines is determining when a hazard is significant and poses an unacceptable risk to the consumer; does this mean that someone has to die first before the guidelines are rigorously applied? Also an issue is the possibility of introducing internationally, water-shipped organisms, such as dinoflagellates, that could cause problems in the future if successfully transferred. Overall, the prognosis among industry members for the live food trade as a high-value, quality market, was very good. Issues of overexploitation, animal welfare, suitable-species selection, reduced mortality and exotic introductions, however, need to be addressed and were just a few of those discussed plenty of food for thought! 1. Department of Ecology & Biodiversity, University of Hong Kong, Pok Fu Lam Road, Hong Kong, China. yjsadovy@hkusua.hku.hk

11 SPC Live Reef Fish Information Bulletin #7 May Ciguatera management by Richard J. Lewis 1 Ciguatera is a global disease caused by the consumption of warm-water fish contaminated with ciguatoxins a family of heat-stable, lipid-soluble, highly oxygenated, cyclic polyether molecules. They have their origin in Gymnodinium toxicus, a benthic dinoflagellate (a type of single-celled algae) at the base of tropical nearshore marine food chains (Lewis & Holmes, 1993). Outbreaks of this algae, and thus of ciguatera, have complex environmental origins beyond the scope of this article. Many species and many families of reef fish can be involved in ciguatera poisoning. Families include the muraenids (moray eels) and lutjanids (e.g. red snappers) which are notorious in the Pacific, serranids (groupers, coral trout, coral cod), lethrinids (emperors), scombrids (tuna-like fishes), carangids (jacks or trevallies) and sphyraenids (barracudas). Ciguatera causes diverse and often long-lasting human health effects. While it is estimated to affect more than 25,000 persons annually (allowing for under reporting), fatalities are rare (~ 0.1% of cases). One exception is ciguatera in the Indian Ocean, which is more often fatal. Some fatalities may be avoided with the introduction of better clinical management practices, including the use of a mannitol therapy, discussed later. While ciguatera is a global problem, it is mostly confined to discrete regions of the Pacific and western Indian Oceans, and the Caribbean Sea. In the Pacific, ciguatera has long been recognised as a widely distributed phenomenon affecting many of the island nations (Banner & Helfrich, 1964). Despite this wide distribution, there are many areas relatively free of ciguatera that are adjacent to areas of high risk. An explanation for such patchiness in the occurrence of ciguatera remains elusive. Current difficulties in predicting, detecting and treating ciguatera mean that this form of fish poisoning will continue to have large socio-economic impacts, particularly in third world countries. Nowhere are these impacts greater than in regions where fish is the principle source of protein, such as the atoll island communities of the Pacific (Lewis, 1992). Symptoms and treatment The symptoms of ciguatera (up to 30 or more) are well described in all regions where ciguatera is a significant problem. Bagnis et al. (1979) described over 3,000 cases of ciguatera in French Polynesia. A similar syndrome is observed in the western and central Pacific (Gillespie et al., 1986). In the Pacific, the onset of the first symptoms can be as short as 30 minutes for severe intoxications, while in milder cases may be delayed for up to 24 or occasionally 48 hours from time of consumption of fish. The first symptoms are often neurological in nature (e.g. tingling of the lips). Some neurological symptoms can take several days to develop, including the reversal of temperature perception (see below), which is highly characteristic for ciguatera. Ciguatera typically lasts for several weeks, but sometimes lasts for months. In a small percentage of cases (estimated <5%) certain symptoms may persist, or may be induced, over a period extending into years. The severity, number and duration of symptoms reflect the combined influence of dose, toxin profile, and individual factors. Gastrointestinal symptoms, such as vomiting, diarrhoea, nausea and abdominal pain, typically occur early in the course of the disease (> ~ 50% of cases), and often, but not always, accompany the neurological disturbances. Neurological disturbances that invariably occur in ciguatera include tingling of the lips, hands and feet, temperature perception disturbances where cold objects give a dry-ice sensation, and an intense itch that moves unpredictably across different patches of skin (> ~ 70% of cases). These symptoms can occur throughout the illness. Generalised disturbances often include a profound feeling of fatigue (90% of cases) that can last throughout ciguatera. Aches of muscles (> 80%), joints (> 70%) and teeth (> 30%) occur to varying extents, and mood disorders including depression and anxiety (50%) occur less frequently. Severe cases of ciguatera can involve hypotension (abnormally low blood pressure) with bradycardia (reduced heartbeat), breathing difficulties and 1. Queensland Agricultural Biotechnology Centre (DPI), Level 7, Gehrmann Laboratories, The University of Queensland 4072, Australia. Fax: ; r.lewis@mailbox.uq.edu.au

12 12 SPC Live Reef Fish Information Bulletin #7 May 2000 paralysis. Some sufferers of ciguatera experience adverse reactions to certain foods, and some victims experience a relapse of the symptoms initially experienced, while intoxicated with alcohol. Differences in symptomatology of ciguatera between the Pacific Ocean, where neurological symptoms predominate, and the Caribbean Sea, where gastrointestinal symptoms predominate, have been shown to arise from different classes of ciguatoxins (Murata et al., 1990; Lewis et al., 1998). The similarity of ciguatera symptoms across the western, central and eastern Pacific, suggests that a class of similar ciguatoxins are involved. A third class of ciguatoxins (yet to be chemically defined) is likely to explain the different symptomology observed in the Indian Ocean (Lewis & Hurbungs, unpubl.). Here fish can accumulate lethal levels of toxin (Habermehl et al., 1994), and produce symptoms reminiscent of hallucinatory poisoning, including lack of coordination, loss of equilibrium, hallucinations, mental depression and nightmares (Quod & Turquet, 1996). Effective treatment of ciguatera requires accurate diagnosis of the syndrome. Presently, ciguatera is a clinically determined disease, diagnosed based on an illness clustered around the recent consumption of a risk fish species. Intravenous mannitol was first introduced as a treatment for ciguatera in the late 1980s (Palafox et al., 1988; Pearn et al., 1989). Diagnosed cases of ciguatera where the patient is not dehydrated are treated with an intravenous infusion of mannitol, given at 1 g/kg over ~ 30 min. In instances where symptoms recur within the first 24 hours after treatment, a second infusion is usually effective. Mannitol is not consistently beneficial, but appears best when used in the acute phase of more severe intoxications. Reasons for a poor response are not known. Symptomatic and supportive therapies still have a role in managing more severe cases, especially for the control of fluid and electrolyte balance. Local anaesthetics and antidepressants may also be useful in some instances. During the recovery phase it is recommended that victims avoid fish and alcohol for 3 6 months, and long-term sufferers should consider whether avoidable foods are contributing to recurrences of symptoms. Avoiding ciguateric fish Presently there is no validated screen for ciguateric fish (Lewis, 1994 and 1995). Antibody assays and sodium channel assays are currently being developed that may provide a much-needed, cost-effective screen for ciguateric fish. Unfortunately, detection of ciguateric fish is made difficult by a number of factors, including the low levels of ciguatoxins present in ciguateric fish (< 0.05 parts per billion for one common type of ciguatera molecule), the multiple structural forms that are present even within a single fish, the absence of any useful chromophore (a part of a molecule that is either coloured or absorbs light in the ulraviolet range making detection easier), the meagre quantities of ciguatera compounds available for research, and the difficulties of synthesising even fragments of these molecules. Analytical methods with the required sensitivity have been developed, but are unlikely to be costeffective for routine screening and require the streamlining of sample preparation (Lewis et al., 1999). Tests that detect the presence of ciguatoxin in patients would overcome the present limitations of differential diagnosis. Difficulties in detecting ciguatera are exacerbated when different classes of ciguatoxins are encountered as in Hong Kong where both Pacific and Indian Ocean ciguatoxins occur. In such instances sodium channel assays have some advantages because they reflect the potency of the toxins present without specific structural requirements. Alternative approaches to monitoring that can reduce the health risk associated with ciguateric fish include: Bans on the capture or trade of certain species; Bans on the capture or trade of fish from certain (high-risk) locations; Recommendations to consume small (<50 g) portions of any one fish; Bans on fish over a certain size (effectiveness not well documented). References BANNER, A.H. & P. HELFRICH. (1964). The distribution of ciguatera in the tropical Pacific. Hawaii Marine Laboratory Technical Report no. 3, University of Hawaii. BAGNIS, R., T. KUBERSKI & S. LAUGIER. (1979). Clinical observations on 3,009 cases of ciguatera (fish poisoning) in the South Pacific. Am. J. Trop. Med. Hyg. 28, GILLESPIE, N.C., R.J. LEWIS, J.H. PEARN, A.T. BOURKE, M.J. HOLMES, J.B. BOURKE & W.J. SHIELDS. (1986). Ciguatera in Australia: occurrence, clinical features, pathophysiology and management. Med. J. Aust. 145, HABERMEHL, G.G., H.C. KREBS, P. RASOANAIVO & A. RAMIALIHARISAO. (1994). Severe ciguatera poisoning in Madagascar: a case report. Toxicon 32,

13 SPC Live Reef Fish Information Bulletin #7 May LEWIS, R. J. (1992). Socioeconomic impacts and management of ciguatera in the Pacific. Bull. Soc. Path. Exot. 85, LEWIS, R.J. (1994). Impact of a validated, cost-effective screen for ciguateric fish. Memoirs Qld. Mus. 34, LEWIS, R. J. (1995) Detection of ciguatoxins and related benthic dinoflagellate toxins: in vivo and in vitro methods. In: G.M. Hallegraeff, D.M. Anderson & A.D. Cembella (eds.). Manual on Harmful Marine Microalgae. IOC Manuals and Guides No. 33, UNESCO, France. LEWIS, R. J. & M.J. HOLMES. (1993). Origin and transfer of toxins involved in ciguatera. Comp. Biochem. Physiol. 106C, LEWIS, R.J., J-P. VERNOUX & I.M. BRERETON. (1998). Structure of Caribbean ciguatoxin isolated from Caranx latus. J. Am. Chem. Soc. 120, LEWIS, R.J., A. JONES & J.-P. VERNOUX. (1999). HPLCtandem mass spectrometry for the determination of sub-ppb levels of Pacific and Caribbean ciguatoxins in crude extracts of fish. Anal Chem. 71, LEWIS, R.J., J. MOLGÓ & D.J. ADAMS. (in press). Pharmacology of toxins involved in ciguatera and related fish poisonings. In: L. Botana (ed.). Marine Pharmacology. MURATA, M., A.M. LEGRAND, Y. ISHIBASHI, & T. YASUMOTO. (1990). Structures and configurations of ciguatoxin from the moray eel Gymnothorax javanicus and its likely precursor from the dinoflagellate Gambierdiscus toxicus. J. Am. Chem. Soc. 112, PALAFOX, N.A., L.G. JAIN, A.Z. PINANO, T.M. GULICK, R.K. WILLIAMS & I.J. SCHATZ. (1988). Successful treatment of ciguatera fish poisoning with intravenous mannitol. JAMA 259, PEARN, J.H., R.J. LEWIS, T. RUFF, T. TAIT, J. QUINN, W. MURTHA, G. KING, A. MALLET & N.C. GILLESPIE. (1989). Ciguatera and mannitol: experience with a new treatment regimen. Med. J. Australia 151, QUOD, J.P. & J. TURQUET. (1996). Ciguatera in Reunion Islands (SW Indian Ocean): epidemiology and clinical patterns. Toxicon 34, Grouper/Wrasse Species Survival Group formed I am pleased to announce the formation of a new Specialist Group under the Species Survival Commission (SSC) of the International Union for the Conservation of Nature (IUCN) which specialises in groupers (Serranidae) and wrasses (Labridae). The IUCN SSC is a science-based network of experts located around the world whose mission it is to conserve biological diversity by developing and executing programmes to study, save, restore and manage wisely species and their habitats. Specialist groups carry out the main work of the SSC and are organised by species or group of species, by region, and/or by conservation theme or discipline across a wide range of plants and terrestrial and aquatic animals; their members are experts in their respective fields. They are invited and have, as part of their responsibility, to assess the conservation status of their particular species or group of animals. Assessments are carried out according to internationally accepted categories and criteria established by IUCN. For those species determined to be under some level of threat, possible restorative action is identified with a view to maintaining biodiversity and healthy populations. The grouper/wrasse group was formed in 1999 because of growing concerns over the status of several larger groupers and wrasses, which appear to be particularly vulnerable to overharvesting. Two species currently in the live reef fish trade are listed as Vulnerable under IUCN criteria: these are the Humphead (Napoleon or Maori) wrasse, Cheilinus undulatus, and the Giant grouper, Epinephelus lanceolatus. About 16 other grouper species in commercial fisheries worldwide were also included in the 1996 IUCN Red List of Threatened Animals. For further information on this group, please contact me at: yjsadovy@hkusua.hku.hk Yvonne Sadovy, Specialist Group Chair

14 14 SPC Live Reef Fish Information Bulletin #7 May 2000 Review of grouper hatchery technology by Mike Rimmer 1 The following article is a slightly condensed version of an article published in the Grouper Aquaculture Electronic Newsletter, 27 January ( Larval rearing of groupers Successful larviculture of groupers has been constrained by generally poor and irregular survival. The principal constraints to successful larviculture (Kohno et al., 1990 and 1997; Tamaru et al., 1995; Leong, 1998; Rimmer et al., in press) are: 1. the small gape of the larvae and hence their requirement for small prey at first feed; and 2. the occurrence of high mortality at various stages through the larval rearing phase. This document briefly reviews grouper larviculture technology, and summarises the current status of this technology. Taxonomic note Because of the sometimes-confused taxonomic status of groupers, particularly the genus Epinephelus, the literature pertaining to grouper aquaculture commonly misidentifies the species concerned. There is a voluminous literature on E. tauvina, but most of this in fact refers to the estuary cod (or greasy grouper) E. coioides. To add to the confusion, the synonym E. suillus is also sometimes used to refer to E. coioides. The blackspotted cod E. malabaricus is sometimes referred to by its synonym E. salmoides. However, much of the Thai literature on E. malabaricus apparently refers to E. coioides (R. Yashiro, pers. comm.). In the following literature review, references to E. tauvina and E. suillus are assumed to refer to E. coioides, and references to E. salmoides to E. malabaricus. Instances of possible misidentification of E. coioides as E. malabaricus are noted. Status of grouper hatchery technology Eggs of E. coioides, E. fuscoguttatus, Cromileptes altivelis and Plectropomus leopardus take hours to hatch, while the European white grouper, E. aeneus take around 25 hours to hatch (Rimmer et al., in press). Grouper eggs and newly hatched larvae are very sensitive to stress and handling (Predalumpaburt & Tanvilai, 1988; Caberoy & Quinitio, 1998). Handling mortality is minimised by handling only neurulastage eggs (after the formation of the optic vesicles) and by stocking eggs into the culture tanks 2 hours before hatching so that the larvae need not be handled (Lim, 1993; Tamaru et al., 1995; Caberoy & Quinitio, 1998). Grouper larvae are stocked at relatively high density: per litre (Ruangpanit, 1993; Duray et al., 1996) up to 50 per litre (Lim et al., 1986; Aslianti, 1996). The larvae are sensitive to light during the early stages of their development and are generally kept in darkened conditions. Rearing tanks are generally rectangular and range in size from 5 to 30 m 3 (Rimmer et al., in press). Tank size, shape and colour may affect the survival of grouper larvae cultured intensively. E. coioides larvae cultured in 3 m 3 tanks demonstrated a better survival rate (19.8%) at Day (D) 24 compared with only 7.4% for those in 0.5 m 3 tanks at D21 (Duray et al., 1997). Growth and survival of E. fuscoguttatus larvae was improved using cylindrical rather than rectangular larval rearing tanks (Waspada et al., 1991b). Cromileptes altivelis larvae exhibited higher survival in green or blue coloured tanks than in red or yellow coloured tanks, but growth rate was not affected by tank colour (Aslianti et al., 1998). Grouper larval rearing tanks are usually supplied with microalgae (generally Nannochloropsis oculata, formerly known as marine Chlorella), or Tetraselmis sp. at 500 x 10 3 to x 10 6 cells per ml ( green water system) (Ruangpanit, 1993; Tamaru et al., 1995; Watanabe et al., 1996; Leong, 1998; Rimmer, 1998; Rimmer et al., 1998). The microalgae provides a shading effect, provides food for the live prey organisms added to the tanks, and may also be ingested by the larvae (although whether the larvae gain any nutritive value from ingested microalgal cells is unknown). More recently, the use of Isochrysis for greenwater rearing has been shown to improve larval growth and survival (Su et al., 1998). 1. Queensland Department of Primary Industries, Northern Fisheries Centre, Cairns, Queensland, Australia

15 SPC Live Reef Fish Information Bulletin #7 May The mouth of larval groupers generally opens 2 3 days after hatching (D2 3), and the larvae begin feeding soon thereafter (Kitajima et al., 1991; Kungvankij et al., 1986; Ruangpanit, 1993; Ruangpanit et al., 1993; Duray 1994; Doi et al., 1997). Kohno et al. (1997) described the development of the feeding apparatus in E. coioides in detail and suggested that the major difficulties in larval rearing of groupers were attributable to the small size of the bony elements forming the oral cavity, small mouth and body size, poor reserves of endogenous nutrition and lower initial feeding rates. Grouper larvae are initially fed on rotifers, often in combination with oyster trochophores, mussel larvae, sea urchin eggs or barnacle nauplii (Hussain & Higuchi, 1980; Lim, 1993; Ruangpanit, 1993; Tamaru et al., 1995; Watanabe et al., 1996; Rimmer et al., 1998). Oyster trochophores, mussel larvae, sea urchin eggs and barnacle nauplii are around 70 µm in size and are thus small enough to be readily consumed by the larvae (Kungvankij et al., 1986; Tamaru et al., 1995). Small-strain (S-type) rotifers (Brachionus rotundiformis) are too large for newly hatched grouper larvae to ingest. Super-smallstrain (SS-type) rotifers (Brachionus sp.), or S-type rotifers screened to <90 µm, are suitable for grouper larvae at first feed (Lim, 1993; Tamaru et al., 1995; Watanabe et al., 1996; Duray et al., 1997; Su et al., 1997). Optimal prey density during the early larval stages is organisms/ml (Ruangpanit, 1993; Ruangpanit et al., 1993; Tamaru et al., 1995; Wardoyo et al., 1997). The use of copepod nauplii as prey during the early larval rearing of groupers has shown considerable promise in improving larval growth and survival (Hussain & Higuchi, 1980; Doi et al., 1997). Provision of nauplii of calanoid copepods (mainly Pseudodiaptomus annandalei and Acartia tsuensis) and rotifers in rearing tanks, resulted in higher survival and faster growth in E. coioides compared with the use of rotifers alone (Doi et al., 1997; Toledo et al., 1999). E. coioides larvae actively select copepod nauplii in preference to rotifers (Toledo et al., 1997). S-type rotifers are fed from about D7 (Tamaru et al., 1995; Su et al., 1997), and brine shrimp (Artemia franciscana) are introduced from about D10. Brine shrimp are initially fed at 1 3/ml, increasing gradually to 7 10/ml at D25 35 (Ruangpanit, 1993). Higher prey densities (2 3/ml) enhance growth and survival (Duray et al. 1997), as does frequent feeding of brine shrimp (4 5 times per day) (Ruangpanit, 1993; Duray et al., 1997). Grouper larvae fed rotifers and brine shrimp enriched with n 3 HUFAs demonstrate better growth, survival and greater stress endurance than those fed with normal live feeds (Pechmanee et al., 1988; 1993; Pechmanee & Assavaaree, 1993; Chao & Lim, 1991; Dhert et al., 1991; Lim, 1993; Quinitio, 1996). Most laboratories supplement live prey for grouper larvae with microalgae (e.g. Tetraselmis, Chaetoceros), home-made lipid emulsions (egg yolk blended with cod liver oil), or commercially available lipid emulsions or microencapsulated supplements (Ruangpanit 1993; Rimmer et al., in press). Minced fish or shrimp may be introduced from about D35 to wean the larvae (or juveniles) from live to inert feeds (Hussain & Higuchi, 1980; Ruangpanit, 1993; Tamaru et al., 1995). Survival of groupers to metamorphosis is generally low: usually <10% and commonly <1%. Recent reports of survival in experimental conditions are: 1 10% (average 4%) for E. coioides (J. Toledo, pers. comm.) and 1 5% for C. altivelis (K. Sugama, pers. comm.). In addition to low average larval survival, survival is highly variable, and a (relatively) successful larval rearing run can be followed by several runs which have negligible or zero survival. It is this both these aspects, low and irregular survival, that have constrained the application of the existing fingerling production technology to commercial hatchery production. The major causes of mortality in grouper larviculture are: 1. High mortality associated with the commencement of exogenous feeding. This mortality may be associated with the provision of live prey organisms of unsuitable size and nutritional composition, but even when suitable prey types are used, there is generally high mortality at this stage (Ordonio-Aguilar et al., 1995; Duray et al., 1997). 2. Several mortality syndromes have been described for grouper larvae. A commonly reported mortality syndrome is the shock syndrome that occurs in late stage larvae from about D25 (Lim, 1993; Duray et al., 1997). This problem may be related to nutritional deficiencies in the live prey organisms used to feed the larvae, since shock syndrome is symptomatic of low levels of HUFAs in the diet (Cowey & Sargent, 1972). 3. Cannibalism is a major cause of mortality during the later stages of larval rearing, i.e. from D30 35 (Lim, 1993; Tamaru et al., 1995; Rimmer et al., in press). Although cannibalism can be controlled by grading larvae and juveniles into similar size classes, grading is often associated with high mortality because handling commonly induces the shock syndrome seen in late stage larvae (Rimmer et al., in press). Provision of shelter is reported to reduce cannibalism in juvenile E. malabaricus (E. coioides?) (Rimmer et al., in press).

16 16 SPC Live Reef Fish Information Bulletin #7 May 2000 Nutritional requirements of larval groupers The few studies that have been carried out on the nutritional requirements of larval groupers suggest that supplementation of the larval diet with HUFAs improves growth and survival. Waspada et al. (1991c) found higher growth rates of E. fuscoguttatus larvae when they were fed rotifers supplemented with bakers yeast with sardine oil or bakers yeast with cod oil. These treatments had high levels of EPA ( % respectively) but highly variable levels of DHA ( % respectively) (Waspada et al., 1991a). Su et al. (1997) found that growth and survival of larval E. coioides were associated with the fatty acid composition of the larvae. Larvae with high levels of total fatty acids grew faster than those with lower levels, and larvae with high DHA or EPA content (>2 mg/g DW) exhibited better survival (>10%) than those with lower HUFA content. Ruangpanit et al. (1993) reported improved survival of E. malabaricus (E. coioides?) larvae when brine shrimp used for larval rearing were enriched with a cod liver oil / egg yolk emulsion (n 3 HUFA = 450 mg/g) or were supplemented with copepods or the freshwater cladoceran Moina. Dhert et al. (1991) found that supplementation of brine shrimp with an emulsion containing high levels of DHA had little effect on growth or survival of E. coioides larvae, and concluded that application of DHA could be delayed until D25 before mortality due to nutritional deficiency affected E. coioides larvae. Thyroid hormone treatment Lam (1994) and Lam et al. (1994) reported that the levels of the thyroid hormone are higher in buoyant than in non-buoyant E. coioides eggs. The buoyant eggs are more viable than non-buoyant eggs, suggesting a relationship between levels of thyroid hormone and viability. Application of ppm triiodothyronine (T3) or thyroxine (T4) is effective in increasing larval survival and hastening the resorption of the dorsal and anal fins in 2 6 days in contrast to 2 3 weeks in fish not so treated (Tay et al., 1994; de Jesus, 1996; de Jesus et al., 1998). Thyroid hormones can be applied by immersing eggs or larvae in a bath, or by bioencapsulation using rotifers or brine shrimp. De Jesus et al. (1998) concluded that a dose rate of 0.01 ppm T4 is appropriate for accelerated metamorphosis and improved survival in 3- to 4-week old grouper larvae. Commercial grouper larviculture in Taiwan The only commercial hatchery production of grouper fingerlings that has been identified is from Taiwan. Larviculture of groupers (as well as other marine finfish species) in Taiwan is undertaken using either the indoor method or outdoor method, i.e. in concrete tanks indoors or in outside ponds (Rimmer, 1998). Indoor method The indoor method utilises large fibreglass or concrete tanks up to about 100 m 3. The rearing tanks are circular or rectangular in shape, flat-bottomed and with a white or light-coloured interior. Larviculture is undertaken using either greenwater or clearwater techniques. The algal density used for greenwater culture ranges from 50,000 to 500,000 cells/ml. Variables such as algal density are only measured in research hatcheries commercial hatcheries just add algal cells until the desired shade of green is reached (Rimmer, 1998). Generally, eggs are added directly to the larval rearing tanks. Grouper larvae are fed oyster trochophores from first feed (usually D4) for 2 days. Rotifers are also added to the rearing tanks, generally commencing from first feed. Recent research at Taiwan Fisheries Research Institute s Tungkang Marine Laboratory (TML) indicates that a combination of oyster trochophores and small rotifers (either SS-strain, sieved S-strain, or neonates) is the best initial feed (Su et al., 1997). Rotifer densities are maintained at about 2 3/ml until the grouper larvae are large enough to eat brine shrimp or adult copepods, which is when the dorsal and pectoral spines reach the end of the caudal fin. Generally, grouper larvae are able to feed on adult copepods from D16 (water temperature >26 C) or D22 (<26 C) (Rimmer, 1998). Outdoor method The outdoor method of larval rearing is undertaken in concrete or earthen ponds ranging in size from 200 m 2 to 0.5 ha, and, less commonly, to 1 ha. The ponds are filled only 1 2 days before they are stocked with eggs. The inlet is screened with a fine mesh sock filter to exclude potential predators and nuisance species. Stocking density for grouper ranges from about 1 kg of eggs (i.e. c. 1.5 million eggs) in 0.1 ha to 2 kg (c. 3 million eggs) in ha larval rearing ponds (Rimmer, 1998). One or two enclosures formed by a tarpaulin set around a floating support structure are set up in the pond, usually with shadecloth overhead to reduce light intensity, and mild aeration to ensure adequate dissolved oxygen and mixing of the water within the enclosure. The enclosures range in size from 5 m 3 in small concrete ponds, to 8 10 m 3 in earthen ponds ha in area. The enclosures are pumped full of pond water, and fertilised grouper eggs are added to the enclosures. Oyster trochophores are added to the enclosures

17 SPC Live Reef Fish Information Bulletin #7 May from first feed (usually D4) for 2 days, then the larvae are released into the pond. The enclosures allow smaller quantities of oyster trochophores to be fed while retaining relatively high prey densities. They also allow the farmer to visually estimate larval survival after the first few days of culture, which is the period when most mortality occurs. If survival is very low, the farmer may choose to restock the enclosure with another batch of larvae, rather than release the survivors into the pond (Rimmer, 1998). Rotifers (and, incidentally, other zooplankters) are cultured in small concrete or earthen ponds, usually about ha. The rotifers are cultured using trash fish placed in fertiliser bags and left to decompose in a corner of the pond, or by the addition of organic wastes. A paddle-wheel aerator is placed in the pond to assist with aeration and to generate a current in the pond. Zooplankton is harvested using a fine (c. 85 µm) mesh net that is set downstream from the paddle-wheel aerator for 1 2 hours. The collected zooplankton is added to the larval rearing pond. Farmers attempt to maintain rotifer density at about 3 4/ml, but, as is the case with other aspects of pond management, rotifer density is not measured, but is maintained by eye. Later in the larval rearing cycle, adult copepods are harvested from the zooplankton production ponds using the same technique, although with a larger mesh (c. 210 µm) mesh net. Some farms pump water from the rotifer production ponds into the larval rearing pond, and may also pump zooplankton-rich water from grow-out ponds into the larval rearing ponds (Rimmer, 1998). The larvae are reared in the ponds until they reach cm total length (TL), when they are harvested. In the case of grouper, this takes about 4 weeks. Pond temperatures need to be above 20 C to ensure any larval survival for grouper; if pond temperatures drop below 18 C, the grouper larvae will die. For this reason, some farms will not purchase grouper larvae until April, even though eggs are available from early March. In addition, farmers feel that the quality of eggs produced early in the season is inferior to that of eggs produced later in the season. Survival of groupers using both indoor and outdoor larval rearing methods is highly erratic, but generally low: 7 per cent survival is regarded as good. Researchers at TML report that a major constraint to grouper aquaculture is the irregular nature of larval survival. The major problem, according to TML researchers, is high mortality at first feed, although there is often low-level mortality throughout the larval rearing process (Rimmer, 1998). Because of the generally low survival of groupers in larviculture, prices for grouper fingerlings are relatively high: US$ 2 3 per fingerling (Tamaru et al., 1995). References ASLIANTI, T. (1996). Larval rearing of the grouper Cromileptes altivelis at different stocking densities. Jurnal Penelitian Perikanan Indonesia 2(2), (In Indonesian, English abstract). ASLIANTI, T., WARDOYO, J.H. HUTAPEA, S. ISMI & K.M. SETIAWATI. (1998). The polka dots grouper Cromileptes altivelis larval rearing under different colours of tank. Jurnal Penelitian Perikanan Pantai 4(3), (In Indonesian, English abstract). CABEROY, N.B. & G.F. QUINITIO. (1998). Sensitivity of grouper Epinephelus coioides eggs to handling stress at different stages of embryonic development. The Israeli Journal of Aquaculture Bamidgeh 50, CHAO, T.M. & L.C. LIM. (1991). Recent developments in the breeding of grouper (Epinephelus spp.) in Singapore. Singapore Journal of Primary Industries 19, COWEY, C.B. & J.R. SARGENT. (1972). Fish Nutrition. Advances in Marine Biology 10, DE JESUS, E.G. (1996). Do thyroid hormones play a role in the metamorphosis of the grouper, Epinephelus coioides? In: J. Joss (ed.). The Third Congress of the Asia and Oceania Society for Comparative Endocrinology, January 1991, pp Macquarie University, Sydney, Australia. DE JESUS, E.G., J.D. TOLEDO & M.S. SIMPAS. (1998). Thyroid hormones promote early metamorphosis in grouper (Epinephelus coioides) larvae. General and Comparative Endocrinology 112, DHERT, P., L.C. LIM, P. LAVEAS, T.M. CHAO, R. CHOU, & P. SORGELOOS. (1991). Effect of dietary essential fatty acids on egg quality and larviculture success of the greasy grouper (Epinephelus tauvina, F.): preliminary results. In: P. Lavens, P. Songeloos, E. Jaspers and F. Elsevier (eds). Fish and Crustacean Larviculture Symposium August Ghent, Belgium DOI, M., J. TOLEDO, M.S.N. GOLEZ, M. DE LOS SANTOS & A. OHNO. (1997). Preliminary investigation of feeding performance of larvae of early red-spotted grouper, Epinephelus coioides, reared with mixed zooplankton. Hydrobiologia 358, DURAY, M.M. (1994). Daily rates of ingestion of rotifers and artemia nauplii by laboratory-

18 18 SPC Live Reef Fish Information Bulletin #7 May 2000 reared grouper larvae Epinephelus suillus. Philippines Science 31, DURAY, M.M., C.B. ESTUDILLO & L.G. ALPASAN. (1996). The effect of background colour and rotifer density on rotifer intake, growth and survival of the grouper (Epinephelus suillus) larvae. Aquaculture 146, DURAY, M.M., C.B. ESTUDILLO & L.G. ALPASAN. (1997). Larval rearing of the grouper Epinephelus suillus under laboratory conditions. Aquaculture 150, eggs in greasy grouper, Epinephelus tauvina. Singapore Journal of Primary Industries 22, LEONG, T.S. (1998). Chapter 13 Grouper Culture. In: S.S. De Silva (ed.). Tropical Mariculture. Academic Press, London LIM, L.C. (1993). Larviculture of the greasy grouper Epinephelus tauvina F. and the brown-marbled grouper E. fuscoguttatus F. in Singapore. Journal of the World Aquaculture Society 24, HUSSAIN, N.A. & M. HIGUCHI. (1980). Larval rearing and development of the brown spotted grouper, Epinephelus tauvina (Forskål). Aquaculture 19, KITAJIMA, C., M. TAKAYA, Y. TSUKASHIMA & T. ARAKAWA. (1991). Development of eggs, larvae and juveniles of the grouper, Epinephelus septemfasciatus reared in the laboratory. Japanese Journal of Ichthyology 38, KOHNO, H., S. DIANI, P. SUNYOTO, B. SLAMET & P.T. IMANTO. (1990). Early developmental events associated with changeover of nutrient sources in the grouper, Epinephelus fuscoguttatus, larvae. Bulletin Penelitian Perikanan (Fisheries Research Bulletin) Special Edition No.1, KOHNO, H., S. DIANI & A. SUPRIATNA. (1993). Morphological development of larval and juvenile grouper, Epinephelus fuscoguttatus. Japanese Journal of Ichthyology 40, KOHNO, H., R.S. ORDONIO-AGUILAR, A. OHNO & Y. TAKI. (1997). Why is grouper larval rearing difficult?: an approach from the development of the feeding apparatus in early stage larvae of the grouper, Epinephelus coioides. Ichthyological Research 44, KUNGVANKIJ, P., L.B. TIRO, B.P. PUDADERA & I.O. POTESTAS. (1986). Induced spawning and larval rearing of grouper (Epinephelus salmoides, Maxwell). In: J.L. Maclean, L.B. Dizon & L.V. Hosillos (eds). Proceedings of the First Asian Fisheries Forum, Asian Fisheries Society, Manila, Philippines. LAM, T.J. (1994). Hormones and egg/larval quality in fish. Journal of the World Aquaculture Society 25, LAM, T.J., T.M. CHAO, L.C. LIM, D. NUGEGODA & A.M. YONG. (1994). Thyroid hormone levels are higher in buoyant than in non-buoyant LIM, K.J., C.L. YEN, T.S. HUANG, C.Y. LIM & C.L. CHEN. (1986). Experiment of fry nursing of E. salmonoides and its morphological study. Bulletin of the Taiwan Fisheries Research Institute 40, ORDONIO-AGUILAR, R., H. KOHNO, A. OHNO, M. MOTEKI & Y. TAKI. (1995). Development of grouper, Epinephelus coioides, larvae during changeover of energy sources. Journal of Tokyo University of Fisheries 82, PECHMANEE, T. & M. ASSAVAAREE. (1993). Nutritional value of rotifer, Brachionus plicatilis, fed with emulsified oils rich in n 3 HUFA. In: The Proceedings of Grouper Culture, November 30 December 1, Songkhla, Thailand National Institute of Coastal Aquaculture, Department of Fisheries, Thailand, and Japan International Cooperation Agency. PECHMANEE, T., M. ASSAVAARCE, P. BUNLIPTANON & P. AKKAYANON. (1988). Possibility of using rotifer, Brachionus plicatilis, as food for early stage of grouper larvae, Epinephelus malabaricus. Technical Paper No. 4. National Institute of Coastal Aquaculture, Department of Fisheries, Thailand. (In Thai.) PECHMANEE, T., P. SOMAUEB, M. ASSAVAAREE & S. BOONCHUAY. (1993). The amount of n 3 HUFA in Chlorella sp. and Tetraselmis sp. In: The Proceedings of Grouper Culture, November 30 December 1, Songkhla, Thailand National Institute of Coastal Aquaculture and Japan International Cooperation Agency. PREDALUMPABURT, Y. & D. TANVILAI. (1988). Morphological development and the early life history of grouper, Epinephelus malabaricus, Bloch and Schneider (Pisces: Serranidae). Report of Thailand and Japan Joint Coastal Aquaculture Research Project 3. National Institute of Coastal Aquaculture, Songkhla, Thailand

19 SPC Live Reef Fish Information Bulletin #7 May QUINITIO, G.F. (1996). The status of grouper and other coral reef fishes seed production in the Philippines. Paper presented at Workshop on Aquaculture of Coral Fishes and Sustainable Reef Fisheries, 4 8 December. Kota Kinabalu, Sabah, Malaysia. RIMMER, M.A. (1998). Grouper and snapper aquaculture in Taiwan. Austasia Aquaculture 12(1), 3 7. RIMMER, M.A., K.C. WILLIAMS & M.J. PHILLIPS. (in press). Proceedings of the Grouper Aquaculture Workshop held in Bangkok, Thailand, 7 8 April RUANGPANIT, N. (1993). Technical manual for seed production of grouper (Epinephelus malabaricus). National Institute of Coastal Aquaculture, Department of Fisheries, Ministry of Agriculture and Cooperative, and The Japan International Cooperation Agency. 46 p. RUANGPANIT, N., P. BOONLIPTANON & J. KONG- KUMNERD. (1993). Progress in the proportion and larval rearing of the grouper, Epinephelus malabaricus. In: The Proceedings of Grouper Culture, 30 November December 1, National Institute of Coastal Aquaculture, Songkhla, Thailand and Japan International Cooperation Agency. SU, H.M., M.S. SU & I.C. LIAO. (1997). Preliminary results of providing various combinations of live foods to grouper (Epinephelus coioides) larvae. Hydrobiologia 358, SU, H.M., M.S. SU & I.C. LIAO. (1998). The culture and use of microalgae for larvae rearing in Taiwan. In: Abstracts of the Joint Taiwan Australia Aquaculture and Fisheries Resources and Management Forum, held at Keelung, Taiwan, 2 8 November p. 28. TOLEDO, J.D., S.N. GOLEZ, M. DOI & A. OHNO. (1999). Use of copepod nauplii during early feeding stage of grouper Epinephelus coioides. Fisheries Science 65, WARDOYO, K.M. SETIAWATI, S. ISMI, J. HUTAPEA & T. ASLIANTI. (1997). Effect of rotifer density on growth and survival rate of polka dots grouper larvae (Cromileptes altivelis). In: Prosiding Simposium Perikanan Indonesia II, Ujung Pandang, 2 3 December (In Indonesian, English abstract). WASPADA, MAYUNAR & T. FATONI. (1991a). Nutrient enrichment of rotifers, Brachionus plicatilis, to support fry production of grouper, Epinephelus fuscoguttatus. Jurnal Penelitian Budidaya Pantai 7, (In Indonesian, English abstract). WASPADA, S. MURTININGSIH, T. AHMAD & M. SUHARJO. (1991b). Effect of different tank shapes on the growth and survival rate of grouper, Epinephelus fuscoguttatus larvae. Jurnal Penelitian Budidaya Pantai 7, (In Indonesian, English abstract). WASPADA, Y. SETIAWAN & M. RODIF. (1991c). Effect of enriched rotifers, Brachionus plicatilis on the growth and survival rate of grouper, Epinephelus fuscoguttatus, larvae. Jurnal Penelitian Budidaya Pantai 7, (In Indonesian, English abstract). WATANABE, W.O., S.C. ELLIS, E.P. ELLIS, V.G. LOPEZ, P. BASS, J. GINOZA & A. MORIWAKE. (1996). Evaluation of first-feeding regimens for larval Nassau grouper Epinephelus striatus and preliminary pilot-scale culture through metamorphosis. Journal of the World Aquaculture Society 27, TAMARU, C.S., F. CHOLIK, J.C-M. KUO & J.JR. FITZGERALD. (1995). Status of the culture of milkfish (Chanos chanos), striped mullet (Mugil cephalus) and grouper (Epinephelus sp.). Reviews in Fisheries Science 3(3), TAY, H.C., J. GOH, A.N. YONG, H.S. LIM, T.M. CHAO, R. CHOU et al. (1994). Effect of thyroid hormone on metamorphosis in greasy grouper, Epinephelus tauvina. Singapore Journal of Primary Industries 22, TOLEDO, J.D., S.N. GOLEZ, M. DOI & A. OHNO. (1997). Food selection of early grouper, Epinephelus coioides, larvae reared by the semiintensive method. Suisanzoshoku 45,

20 20 SPC Live Reef Fish Information Bulletin #7 May 2000 Cyanide fishing on Indonesian coral reefs for the live food fish market What is the problem? Peter J. Mous 1, Lida Pet-Soede 2, Mark Erdmann 3, Herman S.J. Cesar 4,Yvonne Sadovy 5 & Jos S. Pet 6 Abstract According to three precautionary estimations, the reef-degrading capacity of the cyanide fishery for food fish on Indonesia s coral reefs amounts to a loss of live coral cover of 0.047, and m 2 per 100 m 2 of reef per year. These estimates for the rate of coral cover loss are low compared to published rates of natural coral recovery. Differences in growth rate between species of hard coral will cause coral reefs to take longer to recover from the effects of cyanide fishing than a direct comparison of the rate of coral cover loss with published rates of natural coral recovery would suggest. Still, the cyanide fishery for food fish may not be as threatening to Indonesia s coral reefs as is sometimes assumed, especially not as compared to other threats such as blast fishing (responsible for a loss of live coral cover amounting to 3.75 m 2 per 100 m 2 of reef per year, (Pet-Soede, Cesar & Pet, 1999)), or coral bleaching caused by global climate change (cf. Hoegh Guldberg, 1999). Setting the input variables for the estimates at extreme values did not change these conclusions substantively. The depletion of grouper stocks by the trade in live reef food fish, however, is worrying from both fisheries and conservation perspectives. Strategies to abate the depletion of these grouper stocks should not only consider cyanide fishing, but also other fishing methods. 1. Introduction The Live Reef Food Fish Trade (LRFFT) has rapidly expanded throughout Southeast Asia and beyond during the 1990s, and the demand for live fish is projected to grow even more in the future (Dragon Search, 1996). The trade concentrates on the catch of groupers (Serranidae, especially Cromileptes altivelis and species of Plectropomus and Epinephelus) and Napoleon wrasse (Cheilinus undulatus), catering to high-end customers who are willing to pay up to hundreds of dollars (US$) per serving (Johannes & Riepen, 1995). These fish are top predators, sedentary in character and strongly territorial; they are typically long-lived and slow growing; many assemble in large numbers to spawn. These characteristics contribute to the rampant overexploitation engendered by the LRFFT, which has already led to calls to include many of the target species in Appendix II or III of the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) (Lau & Parry-Jones, 1999). Two of the target species (Cheilinus undulatus and the giant grouper Epinephelus lanceolatus) are currently listed as vulnerable on the International Union for the Conservation of Nature (IUCN) Red List (Baillie & Groombridge, 1996). Besides the problem of overexploitation of target species, there is a concern that one of the most widely used capture methods, the application of cyanide solution to stun the fish, is causing severe reef degradation (Johannes & Riepen, 1995). The perceived problem of reef degradation, together with the intriguing nature of the trade has attracted public attention, put pressure on policy makers to abate cyanide fishing, and created a greater willingness among environmental organisations to get involved in the LRFFT issue (Johannes & Riepen, 1995; Pratt, 1995; Barber & Pratt, 1997a; 1997b). However, there is still considerable uncertainty about the extent of the coral reef degradation by cyanide fishing for live food fish. Laboratory experiments showed that exposure of zooxanthellate hard coral to a range of cyanide doses likely to occur during cyanide fishing results in coral bleaching or death of the polyps (Jones & Steven, 1. The Nature Conservancy Coastal & Marine Program, Indonesia. pmous@attglobal.net 2. Fisheries Management Consultant. lidapet@attglobal.net 3. University of California, Berkeley & Indonesian Institute of Sciences. flotsam@manado.wasantara.net.id 4. Institute of Environmental Studies, Free University Amsterdam & Environmental Economics Consulting (CEEC). herman.cesar@ivm.vu.nl 5. The Department of Ecology and Biodiversity, The University of Hong Kong, Hong Kong, People s Republic of China. yjsadovy@hkusua.hku.hk 6. The Nature Conservancy Coastal & Marine Program, Indonesia. jpet@attglobal.net

21 SPC Live Reef Fish Information Bulletin #7 May ). Bleaching of corals is caused by cyanide affecting the photosynthesis of the symbiotic zooxanthellae (Jones & Hoegh-Guldberg, 1999; Jones, Kildea & Hoegh-Guldberg, 1999). However, the toxicity of cyanide to corals under experimental conditions is, in itself, no proof for degradation on the scale of a reef. This is because the rate of coral loss due to cyanide fishing may be lower than the rate of natural coral growth, or it may be that under natural conditions cyanide is dissipated too rapidly by water currents to affect exposed corals (cf. Jones & Steven, 1997). It is also unclear how reef degradation from the cyanide fishery for live food fish compares to the problem of overexploitation of target fish and to the problem of reef degradation caused by other destructive fishing techniques. Erdmann & Pet- Soede (1996, 1999) and others have previously suggested that the reef degradation from cyanide fishing may be wrongly emphasised, and that the more important issue requiring attention in the LRFFT is the potential for overexploitation of the target species (irrespective of capture technique). McManus, Reyes & Nanola (1997) have concurred that reef degradation from cyanide fishing in the LRFFT certainly is minimal compared to that wrought by blast fishing. Unfortunately, quantitative figures are generally lacking to help clarify this debate. One exception is the model of the effects of destructive fishing methods on coral cover in Bolinao (Philippines), which gives an estimate of a decrease of only 0.4% live coral cover per year due to destruction by cyanide fishing for ornamental fishes (McManus, Reyes & Nanola, 1997). In an attempt to further clarify this debate and thereby better focus attention on the LRFFT issues most worthy of action, we have quantitatively estimated the reef degradation potential of cyanide fishing in the LRFFT in Indonesia by three independent methods, using both data from published reports and the authors collated experience with cyanide fishing. We hope that this opinion paper will stimulate additional information inputs that are needed to make decisions on how reef conservation dollars may best be directed. 2. Calculation of the effects of cyanide fishing on coral reefs One way to assess the degradation afflicted by the LRFFT is to estimate what amount of reef is being destroyed per fish caught with cyanide, and multiply this by an estimate of the number of fish caught by the cyanide fishery. Even though this method requires the input of imprecise variables, this method should provide a crude approximation of the order of magnitude of reef degradation caused by cyanide fishing in the LRFFT. In the Spermonde Archipelago (Central Indonesia), on average one bottle (0.5 1 L) of cyanide solution is used to catch one fish (Pet & Pet-Soede, 1999). We assumed this fully destroys live coral cover in an area of one square metre, both by poisoning the coral polyps and by the fisher breaking away coral to extract the stunned fish. Based on personal observations, this figure of one square metre is probably an over-estimation for reefs with a relatively high cover of massive coral structures, as retrieving stunned fish that hide in the cavities under these massive structures will not require nearly as much breakage as retrieving fish that hide between branching corals. Additionally, squirted fish often flee their shelters, thus the damage to coral by the diver retrieving the fish is minimised (pers. observ.). Even the chemical damage per fish caught may be limited to an area smaller than one square metre (pers. observ.; Erdmann & Pet-Soede, 1996). Finally, this figure may result in an over-estimation of the reefdegrading capacity of the LRFFT because we assumed that the killing area was fully covered with live coral. However, we decided to use the one-square-metre figure because we felt that the consequences for management of under-estimating the reef-degrading capacity of the LRFFT, i.e. allowing the cyanide fishery to continue, would be more severe than consequences of over-estimation, i.e. directing too many resources to the abatement of the cyanide fishery (precautionary approach). The estimate of reef area destroyed per fish caught, using Indonesia as an example, was multiplied by the number of fish caught per km 2 per year, which was derived from: 1. the potential production and yield of grouper on pristine coral reefs where exploitation has only just begun, usually by large-scale operations (Pet & Pet-Soede, 1999); 2. the mean observed effort of cyanide fishers times the estimated catch per unit of effort (CPUE) in situations where reefs have already been exploited for some time, and where the most fish are caught by medium-scale operations (Pet & Pet-Soede, 1999); 3. the volume of the LRFFT in Hong Kong, a significant proportion of which comes from Indonesia. In Indonesia live food fish is also caught by other methods, mainly hook-and-line and bamboo traps (pers. observ.; Erdmann & Pet-Soede 1999), but we adopted a precautionary approach by assuming that all fish were caught with cyanide.

22 22 SPC Live Reef Fish Information Bulletin #7 May Method I: Estimation based on the potential production and yield of groupers Estimates for the Maximum Sustainable Yield (MSY) of groupers in other coral reefs average 1000 kg per km 2 coral reef per year (Russ 1991; Jennings & Polunin 1995). If a pristine reef were to be exploited at a rate higher than this MSY, this would eventually lead to lower catch rates. We assumed an exploitation rate for the first year of twice the MSY, i.e kg per km 2 per year, because the LRFFT tends to over-exploit its fishing grounds (Bentley, 1999). The average individual size of fish caught by large-scale cyanide fishing operations in relatively pristine areas has been estimated at 3.33 kg (Pet & Pet-Soede, 1999), about 2 kg heavier than the overall average size of fish encountered in the LRFFT (Johannes & Riepen, 1995). Hence, the total catch amounts to 600 fish per km 2 reef area, resulting in an estimated loss in coral cover of m 2 per 100 m 2 of reef per year. 2.2 Method II: Estimation based on fishing effort and CPUE In Komodo National Park, a creel survey was conducted in 1997 to describe patterns in resource use. During this survey, which covered the full surface area of the Park and which was repeated 18 times during the 12-month period, the number of fishing operations using hookah compressors was recorded. Most, if not all, of the hookah compressor operations in the Komodo area use cyanide to catch live fish (pers. observ.). The crew, usually consisting of c. five persons of whom two were hookah divers, operated from a motorised boat making trips of three days each. At that time, the ban on cyanide fishing was not enforced, mainly because it was usually impossible to obtain legal proof that cyanide was actually used. The number of cyanide operations in the Park seemed high compared to areas outside Park boundaries, probably because fishing opportunities within Park boundaries were still good. Within the boundaries of the Park, on average 3.2 medium-scale cyanide operations per day were encountered (Pet, 1999). The coral reef area in the Park, estimated as a 50-m wide strip following the perimeter of all islands including their shallow reef areas, was c. 17 km 2. Therefore, the daily effort per km 2 of coral reef averaged 0.19 operations. Estimates for the catch per trip in Komodo were not available. Therefore a catch estimate was used from the Spermonde Archipelago, an area approximately 400 km from Komodo. In Spermonde, an operation of similar size uses about 7.5 bottles of cyanide to catch an equal number of fish during each of the two days that fishing actually takes place (Pet & Pet-Soede, 1999). Therefore, the total area potentially destroyed was 7.5 fish times 0.19 operations times 365 days times one m 2, i.e. 520 m 2 per km 2 reef area. Assuming that the targeted reef patches were fully covered with live coral, it follows that the rate of live-coral-cover loss amounts to m 2 per 100 m 2 of reef per year. 2.3 Method III: Estimation based on the volume of the trade in live reef food fish The annual imports of live reef fish into Hong Kong amounted to c. 32,000 tonnes in It is believed that Hong Kong accounts for c. 60 per cent of the total LRFFT volume, and that 50 per cent of all live reef fish originates from Indonesia (Johannes & Riepen, 1995; Lau & Parry-Jones, 1999). Hence, the total amount of fish from Indonesia that reached their destination must have amounted to 27,000 tonnes. This estimate is high (see appendix), but we used it purposefully to ensure we did not underestimate the capacity of the live reef fish trade to damage the reef. Assuming that 50 per cent of all fish caught dies shortly after catching or during transport (Johannes & Riepen, 1995; Indrawan, 1999), the annual catch from Indonesia s coral reefs (85,707 km 2, Tomascik et al., 1997) amounts to 54,000 tonnes, or 630 kg per km 2 per year. Assuming that most fish caught originated from medium-scale operations, the average body weight of the fish in the landings was 1.33 kg (Pet & Pet- Soede, 1999). It follows that the associated rate of live-coral-cover loss would be m 2 per 100 m 2 of reef per year. 2.4 Sensitivity analysis To assess to what extent the methods presented above may be under- or over-estimating the actual reef degradation by the cyanide fishery, we did the same calculations with each of the variables set at what we considered extreme values (Table 1). It should be noted that the minimum and maximum estimates relate to averages over a year, for all over Indonesia, which is why our lower and higher extreme values, which we named conservative and worst (Table 1), may appear not so extreme to some readers. For example, there are reports of whole shipments of live fish dying, but it would not be correct to use this record as a lower estimate for post-harvest mortality in our calculations, because there will also be shipments with little mortality. Also, the resulting lower and maximal estimates for reef degradation are extremes in a sense that we think it is unlikely that all variables are either on the conservative side, or on the worst-case side. However, the extreme estimates can be interpreted as a means to assess the risk of drawing the wrong management conclusions.

23 SPC Live Reef Fish Information Bulletin #7 May The conservative estimates for loss of coral cover caused by the LRFFT ranged between and m 2 per 100 m 2 of reef per year, whereas the worst-case estimates ranged between 0.5 and 0.7 m 2 per 100 m 2 of reef per year. 3. Conclusions & discussion The estimates for loss in live coral cover caused by the cyanide fishery for food fish in Indonesia ranged between 0.05 and 0.06 m 2 per 100 m 2 of reef per year. Though the values for the various variables used in each of the three methods are only approximate, all methods arrived at a level of reef degradation that was of the same order of magnitude. These estimates for reef degradation are low, both considered by themselves and as compared to reported values for reef recovery. The conservative estimate suggests a negligible amount of reef degradation caused by the LRFFT: after a century of cyanide fishing at its present level of effort, only 0.4 m 2 per 100 m 2 of live coral cover would be lost. Even according to the worst-case estimates, it would still take the LRFFT about 40 years to decrease live coral cover by 25 m 2 per 100 m 2 of Table 1. Results of the sensitivity analysis for the estimation of reef degradation, expressed as the yearly loss of live coral cover in m 2 per 100 m 2 of reef, caused by the Live Reef Food Fish Trade (LRFFT). For each input variable, a range of likely values was estimated by the authors. 'Best': Best precautionary estimate (equals the arithmetic or geometric mean of the extremes of the range). 'Conservative': Extreme of the range that leads to more conservative estimates for reef degradation. 'Worst case': Extreme of the range that leads to higher estimates for reef degradation. Method / variable Best Conservative Extremes Worst case Area of live coral cover lost per cyanide bottle used or per fish caught (m 2 ) Method I: Potential production and yield of groupers in pristine areas exploited by large-scale operations MSY (kg. km -2 coral reef. yr -1 ) 1, ,000 Body weight per fish (kg) * Reef degradation ** Method II: Fishing effort and CPUE of medium-scale operations Effort (trips day -1. km -2 reef) Fish caught per unit of effort Reef degradation ** Method III: Volume of LRF, mostly caught by medium-scale operations Hong Kong imports (tonnes) 32,000 25,600 38,400 Through Hong Kong (%) From Indonesia (%) Post-harvest mortality (%) Body weight of fish (kg) * Reef degradation ** * The average body weight for fish caught was set at a higher value in Method I than in Method III, because large-scale operations operating in pristine areas tend to catch larger fish than medium-scale operations that tend to work in areas that have already been fished for some time (Pet & Pet-Soede, 1999). ** Loss of live coral cover, in m 2 per 100 m 2 of reef per year.

24 24 SPC Live Reef Fish Information Bulletin #7 May 2000 reef. As the LRFFT in Indonesia may have been active for 10 years or so (Johannes & Riepen, 1995), it would be exaggerated to state that the LRFFT in Indonesia has already caused widespread damage to the coral reefs. Our best estimate for reef degradation caused by the LRFFT is 40 times lower than the rate of coral cover increase as observed in Komodo National Park (Central Indonesia), where live-coral cover increased by 2 m 2 per 100 m 2 of reef per year after enforcement of the ban of blast fishing (Pet & Mous, 1999). However, this comparison has to be regarded with caution, because increase in live-coral cover does not equal recovery to the state of a pristine coral reef, with its complex structures and its relatively high abundance of the longer-lived hard corals, such as some species of Porites. On the other hand, some reefs seem to be able to re-establish their complexity quickly after near-complete annihilation; after a volcanic eruption and destruction by the lava flow, the reefs around Banda (Eastern Indonesia) recovered completely after a period of five years, featuring 124 species and table coral colonies with a diameter of over 90 cm (Tomascik, van Woesik & Mah, 1996). The damage done by the cyanide fishery for the much smaller sized, ornamental fish is probably much greater than that for food fish, as the number of target fish per unit of reef area is much higher. Also, mechanical reef destruction in the fishery for ornamental fishes may be more extensive, as branching corals are broken apart over large areas, in order to retrieve the small fish (pers. observ.). A relatively high estimate of reef loss inflicted by the fishery for ornamental fish (0.4% reef loss per year) was also suggested by McManus, Reyes & Nanola (1997). The quantification of effects of cyanide squirts on biota other than the target fish and hard corals is hampered by the lack of field data. The risk of adverse long-term effects from cyanide fishing on the environment is probably low, as there are no reports of cyanide bio-magnification or cycling in living organisms (Eisler, 1991). Cyanide seldom persists in surface waters owing to complexation or sedimentation, microbial metabolism, and loss from volatilisation (Eisler, 1991). Our impression was that around the areas where we observed coral bleaching caused by cyanide fishing, there was no evidence for mortality in other benthic organisms. Hence, the estimates for reef degradation presented in Table 1 are likely to pertain to the amount of live-cover loss, including cover of benthic organisms other than hard corals, rather than to the loss of hard-coral coverage exclusively. Mortality in non-target fishes caused by cyanide fishing is even more difficult to quantify. Because of their higher metabolic rate per unit of body weight, smaller fish that were in the direct vicinity of the target fish at the moment of capture most probably die. The mortality probably depends on the rate of dilution of the squirted cyanide, and on the amount of fish that were in the direct vicinity of the target fish. This unknown collateral damage is one of the reasons why we think that cyanide fishing should not be tolerated. In the absence of scientific evidence that shows that the amount of reef degradation is higher than our observation of one square metre per cyanidecaught fish, we must conclude that the reefdegrading capacity of the cyanide-based LRFFT is not as obvious as is sometimes assumed. Therefore, there is a need to get the priorities right when deciding how to allocate reef conservation dollars. There are numerous threats to coral reefs that are beyond doubt (cf. Bryant et al., 1998). Some of these threats, such as global warming (Hoegh-Guldberg, 1999), need to be addressed on a global scale, but others, notably blast fishing (Pet-Soede, Cesar & Pet, 1999) can be addressed cost-efficiently at a local level (Pet, 1997; Pet & Mous, 1999). We are of the opinion that, within the category destructive fishing practices for food fish, blast fishing deserves a higher amount of conservation effort than cyanide fishing. Blast fishing accounts for a loss in live coral cover of 3.75 m 2 per 100 m 2 of reef yearly (Pet-Soede, Cesar & Pet, 1999), which is about 75 times more than our best estimate, and still about 5 6 times more than our worst-case estimate for the loss of coral cover due to cyanide fishing for food fish. The second effect of the LRFFT, the depletion of grouper stocks in their fishing grounds (cf. Bentley, 1999) is more worrying from both conservation and fisheries perspectives. The specific nature of the market for live food fish, where rarity increases the price up to a level where it is economically sound to catch the very last specimen, puts the fish stocks that are targeted by the LRFFT at a high risk (Sadovy & Vincent, 2000). The grouper spawningaggregation sites are easily located by the fishers, and the life-history characteristics of groupers (longevity and size-dependent sex change) make these stocks even more vulnerable to overexploitation (Sadovy, 1997; 1994a). Hence, the size-selective fishing methods practised in the LRFFT affect reproductive success of the exploited stocks in two ways: by extracting the more fecund larger individuals, and by affecting the sex ratio (Johannes et al., 1999). As the target fish are mostly top predators, the LRFFT may also indirectly affect the reef fish community at the lower trophic levels through cascading effects in the food web that are known to exist in both temperate and tropical aquatic food webs (Carpenter, Kitchell & Hodgson, 1985; Goldschmidt, Witte & Wanink, 1993). The problem of over-exploitation cannot be solved by abating

25 SPC Live Reef Fish Information Bulletin #7 May cyanide fishing alone, as it is possible to deplete grouper stocks by other fishing methods (i.e., hook and line) as well (Sadovy 1993; 1994b). Therefore, it is our opinion that the overexploitation is a more severe problem than fishing with cyanide in the LRFFT. The problem of overexploitation can only be solved by putting a proper fisheries management and enforcement framework in place. We strongly support the recommendation in the recent TRAFFIC / WWF report (Lau & Parry-Jones, 1999) to protect spawning aggregations, but we regret that this recommendation is listed under Specific recommendations to address cyanide fishing. Efforts to protect grouper stocks and other stocks targeted by the LRFFT should consider all fishing methods, not only cyanide fishing. Acknowledgements We thank Dr Rodney Salm and Dr Robert E. Johannes for their valuable comments on the manuscript. References BAILLIE, J. & B. GROOMBRIDGE. (1996). IUCN Red List of Threatened Animals. IUCN, Gland, Switzerland. BARBER, C.V. & V.R. PRATT. (1997a). Incentives and private sector partnerships to combat cyanidefishing in the Indo-Pacific region. Paper presented at the Eighth Global Biodiversity Forum, Montreal, Canada, August p. BARBER, C.V. & V.R. PRATT. (1997b). Sullied seas. Strategies for combating cyanide fishing in Southeast Asia and beyond. World Resources Institute, International Marinelife Alliance. 64 p. BENTLEY, N. (1999). Fishing for solutions: can the live trade in wild groupers and wrasses from Southeast Asia be managed? TRAFFIC Report downloaded from BRYANT, D., L. BURKE, J. MCMANUS & M. SPALDING. (1998). Reefs at risk. A map-based indicator of threats to the world s coral reefs. A joint publication by World Resources Institute (WRI), Int. Center for Living Aquatic Resources Management (ICLARM), World Conservation Monitoring Centre (WCMC), and the United Nations Environment Programme (UNEP). 56 p. CARPENTER, S.R., J.F. KITCHELL & J.R. HODGSON. (1985). Cascading trophic interactions and lake productivity. Fish predation and herbivory can regulate ecosystems. BioScience 35: DRAGON SEARCH. (1996). The market analysis of live reef fish in Hong Kong and China. Report prepared by Dragon Search for the Queensland Dept. of Primary Industries. 119 p. + app. EISLER, R. (1991). Cyanide hazards to fish, wildlife, and invertebrates: a synoptic review. U.S. Fish and Wildlife Service, Biological Report 85 (1.23). 54 p. ERDMANN, M.V. (1999). Destructive fishing practices in the Pulau Seribu Archipelago. In: S. Soemodihardjo (ed.). Proceedings of the UNESCO Coral Reef Evaluation Workshop, Pulau Seribu, Jakarta, Indonesia. UNESCO, Jakarta: ERDMANN, M.V. & L. PET-SOEDE. (1996). How fresh is too fresh? The live reef food fish trade in Eastern Indonesia. NAGA, the ICLARM quarterly. 19: 4 8. ERDMANN, M.V. & L. PET-SOEDE. (1999). B6 + M3 = DFP; an overview of destructive fishing practices in Indonesia. In: Proceedings of APEC Workshop on the impacts of destructive fishing practices on the marine environment. Hong Kong, 1997: GOLDSCHMIDT, T., F. WITTE & J. WANINK. (1993). Cascading effects of the introduced Nile perch on the detritivorous / phytoplanktivorous species in the sublittoral areas of Lake Victoria. Conservation Biology 3: HOEGH-GULDBERG, O. (1999). Climate change, coral bleaching and the future of the world s coral reefs. Report to Greenpeace International. 27 p. INDRAWAN, M. (1999). Live reef food fish trade in the Banggai Islands (Sulawesi, Indonesia): A case study. SPC Live Reef Fish Information Bulletin 6: JENNINGS, S. & N.V.C. POLUNIN. (1995). Comparative size and composition of yield from six Fijian reef fisheries. Journal of Fish Biology 46: JOHANNES, R.E. & M. RIEPEN. (1995). Environmental, economic and social implications of the live reef fish trade in Asia and the Western Pacific. Report prepared for The Nature Conservancy. 81 p. JOHANNES, R. E., L. SQUIRE, T. GRAHAM, Y. SADOVY & H. RENGUUL. (1999). Spawning aggregations of Groupers (Serranidae) in Palau. The Nature Conservancy Marine Research Series Publication No p.

26 26 SPC Live Reef Fish Information Bulletin #7 May 2000 JONES, R.J., T. KILDEA & O. HOEGH-GULDBERG. (1999). PAM Chlorophyll fluorometry: a new in situ technique for stress assessment in Scleractinian corals, used to examine the effects of cyanide from cyanide fishing. Marine Pollution Bulletin 10: JONES, R.J. & O. HOEGH-GULDBERG. (1999). Effects of cyanide on coral photosynthesis: implications for identifying the cause of coral bleaching and for assessing the environmental effects of cyanide fishing. Mar. Ecol. Prog. Ser. 177: JONES, R.J. & A.L. STEVEN. (1997). Effects of cyanide on corals in relation to cyanide fishing on reefs. Mar. Freshwat. Res. 48: LAU, P.P.F. & R. PARRY-JONES. (1999). The Hong Kong trade in live reef fish for food. TRAFFIC East Asia and World Wide Fund For Nature Hong Kong, Hong Kong. 65 p. MCMANUS, J.W., R.B.J. REYES & C.L.J. NANOLA. (1997). Effects of some destructive fishing methods on coral cover and potential rates of recovery. Environmental Management 21: PET, J.S. (1997). Destructive fishing practices in and around Komodo National Park. SPC Live Reef Fish Information Bulletin 2: PET, J.S. (1999). Marine resource utilization in Komodo National Park. Monitoring report Report from The Nature Conservancy Coastal and Marine Program Indonesia. 38 p. PET, J.S. & P.J. MOUS. (1999). Status of the coral reefs in and around Komodo National Park Monitoring report prepared by The Nature Conservancy Indonesia Coastal and Marine Program, Jakarta, Indonesia. 21 p. PET, J.S. & L. PET-SOEDE. (1999). A note on cyanide fishing in Indonesia. SPC Live Reef Fish Information Bulletin 5: PET-SOEDE, C., H.S.J. CESAR & J.S. PET. (1999). An economic analysis of blast fishing on Indonesian coral reefs. Environmental Conservation 26: PRATT, V.R. (1995). The growing threat of cyanide fishing in the Asia Pacific region and emerging strategies to combat it. Paper presented at the Global Biodiversity Forum 1995, November , Jakarta, Indonesia. 7 p. RUSS, G.R. (1991). Coral reef fisheries: effects and yields. In: P.F. Sale (ed.). The ecology of fishes on coral reefs. Academic Press Inc. San Diego: SADOVY, Y. (1993). The Nassau grouper, endangered or just unlucky? Reef Encounter 13: SADOVY, Y. (1994a). Aggregation and spawning in the tiger grouper, Mycteroperca tigris (Pisces: Serranidae). Copeia 1994 (2): SADOVY, Y. (1994b). Grouper stocks of the Western Central Atlantic: the need for management and management needs. Proceedings 43rd Gulf Caribbean Fisheries Institute 1994: SADOVY, Y. (1997). The trouble with groupers Living Oceans News Special Issue: 4 5. SADOVY, Y. & A.C.J. VINCENT. (2000). The trades in live reef fishes for food and aquaria: issues and impacts. In: P.F. Sale (ed.). Coral reef fishes: new insights into their ecology. Academic Press. TOMASCIK, T., A.J. MAH, A. NONTJI & M.K. MOOSA. (1997). The ecology of the Indonesian Seas. Part One. Periplus Editions, Singapore. 642 p. TOMASCIK, T., R. VAN WOESIK & A.J. MAH. (1996). Rapid coral colonization of a recent lava flow following a volcanic eruption, Banda Islands, Indonesia. Coral Reefs 15:

27 SPC Live Reef Fish Information Bulletin #7 May Short review on the traded volume of live food fish Appendix Johannes & Riepen (1995, p.4) presented a conservative estimate of total volume of the LRFFT of 20,000 25,000 tonnes per year, and they estimated that about 60 per cent thereof is traded in Hong Kong (Johannes & Riepen, 1995, p. 16). A significant amount of the total volume is cultured, but it remains unclear to what extent the culture is based on the grow-out of wild-caught fish (Johannes & Riepen, 1995, p. 16). For example, the country that is known to produce most of the cultured groupers, Taiwan (Johannes & Riepen, 1995, p. 16) is also an important importer of wild-caught grouper fingerlings from the Philippines (Bentley 1999, pp ). According to the survey of Hong Kong Census and Statistics Department (HK CSD) data by Lau & Perry-Jones (1999, pp. 8 12), the total amount of live marine fish (HK HS Codes , -21, -22, -23, -29, -31, -39, -41, and -99) imported into Hong Kong amounts to 21,000 tonnes, whereof nearly 90 per cent was imported by air. This figure of 21,000 tonnes underestimates the total volume of the LRFFT, as locally licensed, live-reef-fish transport vessels, estimated to import about 10,000 tonnes per year (Johannes & Riepen, 1995, p. 51), are exempt from declaration of imports of live reef food fish (Lau & Perry-Jones, 1999, p. 4). By interviewing 39 of the 114 companies that trade live fish in Hong Kong, imports of the 11 most common species were estimated at 24,000 tonnes per year (Lau & Perry-Jones, 1999, p. 7). These species were: Lutjanus argentimaculatus (21%), Epinephelus coioides (20%), Plectropomus leopardus (18%), P. areolatus (9.7%), E. bleekeri and E. areolatus (both species grouped in one category, 7.6%), E. fuscoguttatus (7.2%), E. polyphekadion (5.0%), E. akaara (3.6%), Cromileptes altivelis (3.0%), Cheilinus undulatus (2.8%) and E. lanceolatus (1.9%). Hence, according to the survey among traders, the total volume of live food fish traded in Hong Kong must have amounted to 32,000 tonnes annually. This is close to the sum of the estimate for the volume of live reef fish (10,000 tonnes) imported by locally licensed vessels (Johannes & Riepen, 1995, p. 51), and the total imports (21,000 tonnes) as estimated by the HK CSD (Lau & Perry-Jones, 1999, pp. 8 12), even though the latter includes a large category (c. 14,000 tonnes) of other live marine fishes (Lau & Perry-Jones, 1999, p. 6). Perhaps problems with species identification caused a considerable part of the trade volume that should have been categorised in one of the other statistical categories to be entered under other live marine fishes. According to Hong Kong importers, Indonesia supplies more than 50 per cent of the wild-caught live reef fish to Hong Kong and Singapore (Johannes & Riepen, 1995, pp. 10 & 35). This figure was close to the estimate of 60 per cent from Bentley (1999, p. 28), which was based on fisheries statistics from the main exporting countries (Indonesia, Philippines and Malaysia). In Lau & Parry-Jones (1999) Indonesia was listed as the only country that exported mouse grouper (Cromileptes altivelis) and giant grouper (Epinephelus lanceolatus), whereas it accounted for 35 per cent of coral trout and 20 per cent of all other groupers (Lau & Parry-Jones, 1999, pp. 8 10). However, as was mentioned earlier, these data pertain almost exclusively to imports by air. According to the Indonesian Directorate General of Fisheries, annual exports of live food fish from Indonesia averaged 3,500 tonnes over (Bentley, 1999, p. 29), whereas Erdmann & Pet (1996, p. 6) present an even lower estimate for total exports of live food fish from Indonesia of 2,200 tonnes annually. Epinephelus coioides